The central figures encountered in the papers are: Eliakim Richards (1775-1852); his wife Susan Hersey Richards (1792-1819); Elias Hersey (b. 1789) and Abel Hersey (1791-1877), Susan's older brothers; Bradford Lincoln (1776-1862); Elizabeth Lincoln (1804-1880) and Martha Lincoln Balch (1811-1882), Bradford's daughters; and Bradford Lincoln, Jr. (1801-1852).

Eliakim Richards was born in Dedham, Massachusetts on 21 February 1775, son of Eliakim and Mary Mayo Richards. His wife, Susan Hersey Richards, was born in Hingham, Massachusetts on 3 December 1792, daughter of Elias Hersey and Susanna Hobart Hersey. The younger Eliakim Richards was a farmer and carpenter. Susan's parents died by the time she turned ten years old and she and her brother Abel Hersey (1791-1877) were placed under the guardianship of Levi Lincoln, Jr., a prominent Massachusetts physician and politician, until her marriage to Eliakim Richards on 11 December 1811. Her oldest brother, Elias Hersey (b. 1789), served as a private in the War of 1812. He and Abel went on to operate various businesses, including money lending and a liquor trade, all with financial support from Eliakim Richards. Susan died in 1819 at the age of twenty-seven. Eliakim remained a widow and eventually died from pneumonia in 1852. The Richards had three children: Katherine, George (1816-1903), and Henry (b. ca.1819). These three individuals do not figure prominently in the papers, but George Richards' marriage in 1842 to Irene Lincoln, daughter of Bradford Lincoln, served as an important link between the two families. George Richards and Irene Lincoln Richards eventually relocated to Montgomery County, Illinois. A short time later, while seeking improved health in the warmer climate of South Carolina, Irene died after a lengthy illness. Upon her death George Richards returned to Illinois.

Bradford Lincoln, the other prominent figure in the papers, was a farmer and hatter in Roxbury, Massachusetts. He was born on 19 October 1776, son of Job and Mercy Lincoln. In 1799 he married Rebecca Austin Atwood (1777-1853); the couple had eight children: Bradford Jr. (1801-1852), Joshua (b. 1802), Elizabeth (1804-1880), Augusta (1807-1828), John (b. 1809), Martha (1811-1882), Irene (1813-1857), and Benjamin (1814-1863). Bradford Lincoln would outlive his wife and many of his children. His wife and daughters Augusta and Irene would all die from tuberculosis. His namesake, Bradford Lincoln, Jr., would die from typhoid, while his son Benjamin would succumb to disease near Beaufort, South Carolina, while teaching freed slaves at Port Royal. Bradford's daughter Irene's passing was yet another blow. Despite Irene's death and absence, Bradford Lincoln decided to sell the family farm in Massachusetts and join his son-in-law, George Richards, his daughter, Elizabeth Lincoln, and son Benjamin Lincoln (prior to his relocation to South Carolina) in a permanent move to Illinois.

According to surviving letters, Bradford Lincoln appears to have had a complicated relationship with his son Bradford Lincoln, Jr. Financial disputes were an ongoing source of contention, even after Bradford, Jr.'s death in 1852. The passing of Bradford, Jr. prompted his wife, Ellen Lincoln, to sue her father-in-law on the grounds that he had signed a promissory note to his son in the amount of $5108. Bradford Lincoln asserted the note was a forgery and that the original agreement was only for $108. The case eventually made its way to the Massachusetts Supreme Court in 1857, where it was ultimately dismissed.

Bradford Lincoln's relationship with Elizabeth and Martha was less strained. Elizabeth Lincoln's letters reveal a close bond between eldest daughter and father. After the death of her younger sister Irene, Elizabeth joined her father in the move to Illinois, in order to assist him and also help her supportive brother-in-law, George Richards, care for his children. Elizabeth remained there as a single woman until her death in 1880. Martha Lincoln Balch, married to Edward Lawrence Balch (1811-1869) of Boston, with one son (William Lincoln Balch, b. 1847), also wrote faithfully and lovingly, both to her father and to her sister Elizabeth. Martha's emotional letters to Illinois describe her daily life in Boston, and also document her reflections on members of her extended family, and her sadness at her separation from them. Martha regularily sent her father newspapers and church bulletins in order to keep him abreast of goings-on back home. Martha Lincoln Balch died in 1882.

For his part, Braford Lincoln remained connected to family and to professional associates in Boston, well after his final move to Illinois around 1858 (he had resisted an earlier invitation from George and Irene in 1843 to move west). At the time of his move Bradford was 83 years old. He wrote back to his closest business associate in Boston proudly claiming his health was very good and life in Illinois very pleasant. Always active, Bradford Lincoln maintained his business dealings in Massachusetts right up until his death in 1862. His son-in-law, George Richards, would ultimately become executor of both his father-in-law's estate, and the estate of his brother-in-law and sister-in-law, Benjamin and Elizabeth.