Colonel Ward Hill Lamon wrote two books about Abraham Lincoln, after the assassination: The Life of Abraham Lincoln, From His Birth to His Inauguration as President (1872) and Recollections of Abraham Lincoln, 1847-1865 (posthumously published in 1895 and republished in 1911, both copyrighted by his daughter, Dorothy Lamon Teillard, after Col. Lamon's 1893 death.)

Before Col. Lamon's words in the 1911 edition of the latter title (held in the Lincoln Room, and archived online by the University of Illinois, Urbana-Champaign), there is a section titled "Memoir of Ward H. Lamon" which doesn't specify authorship, but might be presumed to be Dorothy Lamon Teillard, as she has Editor credit for the volume (and the Memoir section concludes with a very personal anecdote regarding Col. Lamon's passing in the presence of his daughter.) From that memoir section come the following details of Col. Lamon's later life:

On June 10th, 1865, Secretary of State William Seward accepted Col. Lamon's resignation as a U.S. Marshal (a resignation which Lincoln had refused to accept). He practiced law for some years until 1879 when he relocated to Colorado and befriended the then-Editor of the Denver Tribune, Eugene Field (later known better as a humorist and poet). Lamon found some solace in Field's interest in Lincoln, and Field, having been only 12 when Lincoln was assassinated, was fascinated by the firsthand witness accounts Lamon was able to share.

Field relocated to the midwest, and the memoir section jumps forward to Col. Lamon's death "at eleven o'clock on the night of May 7th, 1893." The eleven years between are not addressed in that prefacing memoir.