Lincecum is known for his exploration and settlement of what are now the U.S. states of Alabama, Mississippi, and Texas, which was then beyond the western borders of the Thirteen Colonies.

He sought a new frontier in 1868 and, at the age of seventy-six, with a widowed daughter and her seven children, joined a Confederate colony in Tuxpan, Veracruz, Mexico.

"[3] I remember now, though the time has long passed, with feelings of unfeigned gratitude the many kindnesses bestowed on me and my little family in 1818 and 1819 when we were in their neighborhood before the country began to fill up with other white people ... .

But so long as the life pendulum swings in this old time-shattered bosom, I shall remember their many kindnesses to me and mine, with sentiments of kindest affection and deepest gratitude.Lincecum was a self-taught naturalist.

He published numerous articles in scholarly scientific journals and came to be recognized as a thorough and respectable researcher, despite his lack of formal education.