John Mower Jackson (21 October 1840-2 July 1913) was born in Lewiston, Androscoggin County, Maine, the son of Joseph and Betsey Mower Jackson. Joseph Jackson owned and operated a farm, with real estate appraised at $6,000 in the 1860 Federal census. John Jackson resided at this farm prior to his departure for the army; he was unmarried and, as his letters make clear, had yet to establish himself in a profession (the 1860 census identifies him as a farm laborer). Also living at the farm were three older siblings: Delinda (b. 1831); Alonzo (b. 1833); and Delora (b. 1835).

On 29 September 1862 Jackson was mustered in to Company A of the 23rd Maine Infantry for nine months' service. His time as a private in the 23rd Maine was spent in guard duty along the Potomac; the unit was never engaged. In July 1863 he was mustered out; by November he was employed in Boston, in an unidentified trade. Early in 1864 Jackson reenlisted, and on 23 March was mustered in to Company D of the newly organized 32nd Maine, as 1st sergeant. By the end of April six companies of the 32nd Maine were in Virginia, attached to the 2nd Brigade, 2nd (Potter's) Division of Ambrose Burnside's IX Corps, now operating with the Army of the Potomac. On 3 May Grant moved the army south across the Rappahannock, inaugurating eight weeks of constant campaigning marked by some of the worst fighting of the war. This, the Richmond or Overland campaign, ended with Lee besieged at Petersburg. Jackson remained on active duty throughout the campaign, seeing his first action at Spotsylvania on 12 May. He continued on active service through the first eight weeks at Petersburg, as his regiment melted away due to battle casualties, illness, and fatigue. He finally left the line on 15 August 1864, with an illness (or combination of illnesses) that kept him hospitalized until December. Jackson briefly returned to duty with the 32nd Maine, before being mustered out on 12 December when the regiment was consolidated with the 31st Maine.As a member of the 23rd Maine Jackson was a "nine-months man," recruited under the Federal Militia Act of 17 July 1862. This act empowered the President to call the state militias into national service for nine months (the government understood "militia" to mean all non-exempt civilian men between the ages of 18 and 45; militia companies in the traditional sense had ceased to exist in most Northern states, except on paper). The War Department's General Order No. 94 of 4 August set the wheels in motion, stipulating "[t]hat a draft of 300,000 militia be immediately called into the service of the United States, to serve for nine months unless sooner discharged. The Secretary of War will assign the quotas to the States and establish regulations for the draft." (Official Records, ser. iii, vol. 2, pp. 291-2). The key word was "draft " — a profoundly undemocratic and potentially disruptive instrument, it was believed, and one thus far avoided in the North, though the Confederates had passed a conscription act the previous April. Response to the President's early July call for 300,000 three-year volunteers had been painfully slow. The hope was that the threat of being drafted into the militia would encourage men to volunteer for three years service. By volunteering, recruits had more say in their military destination, and earned the traditional $100 Federal bounty, a deal not extended to draftees or nine-month volunteers.

By the end of 1862 these strategies had drawn about half a million men into the Federal army, most of them three-year volunteers. But what of the militia, and the draft? According to the Official Records, (ser. iii, vol. 5, 1264-5), 87,588 men were mustered into nine-month regiments under General Order 94. Maine supplied 7,620 such men, in eight regiments. Complying with Federal instructions, Governor Israel Washburn completed the enrollment of eligible "militia" in August — but in only a few parts of the state did drafts actually follow, and all efforts at drafting ended in late September. Washburn's sentiments are aptly summarized in a letter to Secretary of War Stanton, dated 11 August:

Many towns, and perhaps entire counties, in Maine wish to furnish their quotas for the nine-months' men by volunteer enlistments. Is their [sic] any objection to such towns furnishing their quotas in this way, to be received as drafted men, subject to all rules applicable to drafted men, but thus preventing a draft being put into the towns so furnishing their quotas? I think this privilege would reduce the expense largely and accelerate filling up our quota. (Official Records, ser. iii, vol. 2, p. 352). To attract volunteers and avoid the stigma of the draft, Washburn authorized and urged the raising of local bounty money, to be paid to nine-month volunteers in lieu of the Federal bounty. Jackson himself was evidently such a volunteer, alert to both the threat of the draft and the availability of the bounty. "Father what do you think now of my having a faint heart on account of the draft?", he writes on 16 October, and on 27-28 October: "Mother I am fairly engaged in 'Uncle Sam's famous Excursion' where the excursionists receive one hundred & fifty dollars in advance & are clothed and fed during the whole Show" (references to nine-month enlistments as "excursion parties" were commonplace in the recruiting literature of 1862). Ultimately, though, Jackson speaks of more idealistic motives for serving in the army:

It makes me provoked when I receive a letter mentioning that I "must be glad when" I "can come home again" & appearing to think that I came for the pleasure or honor of it. A man that has no higher aim I have no more respect for than I have for the cowards that think of staying at home as a matter of saf[e]ty. Our army needs men and I rejoice that they will come from any motive but as far as esteem goes those that come from low principles, though I am glad they are here, I cannot look upon as patriots. (28 April 1863). Moreover, Jackson's time in the 23rd seems to have heightened his sense of his own capabilities. He speaks with pride of his continued good health, his ability to withstand hardship, his willingness to do his duty without complaint. Of course, Jackson saw no combat with the 23rd — other than the snowball battle described in the letter of 18 February 1863. Like most of the nine-month regiments of 1862, the 23rd Maine was earmarked for guard and garrison duty; the Potomac and the defenses of Washington were common enough destinations. Camp routine is neatly summarized in a letter from Edward's Ferry, Maryland of 11 April 1863:

We go on guard once in nine days & on picket about once a month. Order of exercises as follows: Reveille & roll call 5 1/2 oclk morn. Bugle call for breakfast 6 oclk For fatigue & sick 6 1/2 Guard mounting at 7 1/2 Drill from 8 1/2 to 9 1/2 & from 10 1/2 to 11 1/2 Dinner call 12. Drill from 1 1/2 P.M. to 4 Dress parade 4 1/2 Supper call 5. Retreat & roll call sunset Tattoo 8 eve. Taps 8 1/2. Beside this we are required to wash every morn, wash our feet three times per week & our bodies once per week. Sweep out our tent every morn & also sweep for considerable space around our tents. Our blankets all to be hung out before 8 oclk. to air during the day. The Officer of the day inspects our quarters each day and we have an inspection of arms every night. Saturday is set apart for us to wash our clothes and do our mending so you see we have no great time to write except Saturday and Sunday. The great danger, of course, was contagious disease, which appears to have been most prevalent in Jackson's regiment in November and December of 1862. In all, 56 members of the 23rd Maine died of disease; most were probably victims of typhus.

In his letter of 11 April 1863 Jackson reassures his parents that "I shall not come again [i.e., reenlist] unless I think there is need of men & in that case you could not oppose my coming, patriotism would rather cause you to send me". The following March Jackson did reenlist, for three years, in the newly organized 32nd Maine. The regimental history describes the local bounties for returning veterans as "liberal;" still, the 32nd Maine was essentially a "green" regiment, with roughly 14 per cent of its enlisted men (and a higher percentage of its officers) having seen prior service. Jackson's Company D appears to have included only nine veterans, seven of whom had served together in Company A of the 23rd Maine. Most of these were non-commissioned officers in the new company, including Jackson himself, who was 1st sergeant. The 32nd Maine was brigaded with three veteran New Hampshire regiments and two other regiments raised in 1864, the 31st Maine and the 17th Vermont. The brigade was commanded by Colonel Simon Griffin.

The 32nd Maine was not engaged at The Wilderness (4-6 May 1864). It saw its first sustained action on 12 May at Spotsylvania, in an early morning assault by Burnside against entrenchments on the eastern leg of the Confederate "Mule Shoe" salient. Griffin's brigade, on the right, led this assault, which penetrated the opposing lines but was soon thrown back by Confederate counterattacks. This is the "principal fight" mentioned in the brief letter of 14 May. Griffin's brigade attacked again, over much the same ground, on 18 May, and again, the attack netted nothing but casualties. On this occasion the 32nd Maine broke when counterattacked, passing through the ranks of the New Hampshire veterans positioned just to their rear. This engagement is not mentioned in the subsequent letter, written on 25 May from entrenchments just south of the North Anna River (though Jackson does comment that "[t]he N. H. officers have been hard and unjust with us." The letter of 5 June mentions the 32nd Maine's next major action, on the third of June at the battle of Cold Harbor. The regiment was closely engaged but received an eleventh-hour reprieve when a potentially disastrous assault on the Confederate left was cancelled by Grant.

On 15 June Griffin's brigade crossed the James, and after moving through Petersburg's original defenses on the 17th and 18th, dug in on the outskirts of the city. By the end of the month the siege proper had begun. The position occupied by Griffin's brigade from mid-June to mid-August was in the trenches east of the city, along the Norfolk and Petersburg Railroad. The lines in this sector were very close together, and casualties from shelling or sniper fire were a regular occurrence. The two-day intervals spent in the advanced or picket lines were especially hazardous, as Jackson describes in a letter of 4 July:

Last night we came off picket where we had been for forty eight hours. The two lines were not more than about [a] stone's throw from each other & the boys of each side fire at the others just as soon as they can see a head above the works. Our picket line is now an advanced line of battle, that is it is as strong as a line of battle. We fill the line in two ranks. Every day more or less of our boys are killed or wounded. The casualties endured by the Army of the Potomac in May, June, and July of 1864 were fearful. In his letter of 5 June, after Cold Harbor, Jackson notes that Company D had suffered 25 casualties, including seven killed. These totals represented between 25 and 30 per cent of the company's original strength. But casualties accounted for only a fraction of the losses. Some men were made prisoner; others straggled, or simply disappeared; many more fell out sick. Hence Jackson's observations in the same letter that "[w]e now muster but eighteen muskets & have no commissioned officer with us." And this situation worsened; in a letter of 5 July published in the regimental history, Sergeant John L. Ham of Company D notes but thirteen men present for duty, including "[f]irst sergeant John M. Jackson, who has command of the company."(Henry C. Houston, The Thirty-second Maine, p. 302). And the July return for the 32nd Maine as a whole, apparently made out in mid-August, shows three officers and 93 enlisted men as present for duty — an average of fewer than ten men per company. These figures take into account the very significant losses suffered by the regiment at the Battle of the Crater on 30 July — an attack in which Jackson almost certainly participated, but which he never mentions in the surviving letters.

Throughout this period Jackson remained with the regiment, often with the added burden of company command (which he appears not to have relished). "I have stood in very well to march, fight &c," he writes on 13 July, "being the only one left in the Co. that has never straggled or been sick." The letters from Petersburg are notably introspective. On more than one occasion Jackson meditates on the possibility of dying, deriving solace in this regard from his faith:

I look upon war as I never did before. I always knew it was a horrid thing, but each hour reveals new horrors. In my own case I don't realize it so much for I hope if I fall it is only to commence a more glorious life & another thing I have no family that will be thrown on the charities of a selfish and unfeeling world if I die & yet another & by no means small item to me is that soon we should all be reunited in that glorious Land where we shall never be parted more I hope and trust this is our case. (1 July 1864). Another great consolation for Jackson was receiving news from home. Again and again, he urges his parents and sisters to write more and longer letters, for "[it] seems to me I should die if I did not hear from [home] oftener than some of the boys do." (25 June 1864). Letters appear to have buoyed his spirits in a variety of ways. They were affirmations of his family's affection; signs of their recognition of his own suffering; and welcome reminders of the familiar amidst the forbidding world of the trenches. Indeed, one of the avowed purposes of Jackson's own, prolific letter writing was to elicit a steady stream of letters in return.

In mid-August IX Corps was moved about three miles to the left, to support an attack by V Corps along the Weldon Railroad. It was at this point, on 15 August, that Jackson fell back from the regiment:

A few days ago I was bragging that I had never fallen back & all but that is up. I have never fallen back at all until this morn. I have moved about two miles to the left I should think. I wanted to ride in the Ambulance but there was none, so I did not try to come with the Co. I do not feel that I have had really fair play but there is a very natural reason for it. I want to do my duty as a soldier and shall try to. [B]ut I have reached the height of my Ambition as regards being on duty. I have stood to see all the rest of the Co, fall back so I am the last that remained of the boys. I did not get excused from duty but I did fall back and shall not be backward about taking advantage of any chance to rest myself. I am not very well today but I am unwell with a disease that I trust will have left me by tomorrow. Apparently, Jackson was unable or unwilling to complete the march to the regiment's new location. Within days he was in the division hospital at Petersburg, where he remained for about three weeks. On 7 September he was transferred to the general hospital at City Point on the James. On 28 September he writes that he is about to return to the regiment; instead, on 1 October, he was moved "out of the sound of cannon and musketry" to St. Paul's Church Hospital at Alexandria, Virginia. Jackson never speaks of his illness in very specific terms. He does on occasion allude to a general debility, and mentions that "I honestly believe I should have died if I had been kept there [at City Point] very much longer." (19 October 1864). By November he was well enough to travel home on furlough, presumably to vote. In early December he returned up the James to Petersburg to rejoin the regiment. But on 12 December — the very date of Jackson's final, seemingly fragmentary letter — the 32nd Maine ceased to exist. Four hundred eighty-five officers and men (of whom fewer than 200 were actually present in the lines) were formally transferred to the 31st Maine, to create one regiment of average strength. Supernumerary non-commissioned officers of the 32nd were mustered out and discharged, and Jackson was among this number; so ended his military career.

Following the war Jackson married, and farmed near Auburn in Androscoggin County, Maine.