Among his bookkeeping he wrote that in July 1826, they made $243 from evening crowds and from December 1826 to March 1827, they spent $16.50 for exhibiting a rhinoceros.

In 1837, he retired to the estate of his father-in-law, George Patterson, near Schuylkill Haven, Pennsylvania, and lived as a country gentleman, at Woodland Farm.

[9] In October 1855, he began keeping a journal,[8] and he turned to still life painting, as an extension of his interest in natural history.

April 15, 1865: sad news of the murder of President Lincon [sic], he was shot while attending a performance at Fords' Theater last night in Washington.

The assassin entered his private box and shot him in back of his head and then escaped, the assassin's name is ______,April the 22nd: The corpse arrived this afternoon from Harrisburg and it was dark, and although the square was brilliantly illuminated with greek lights each side of the great walk Red, Blue & White, which made a most brilliant appearance and lighted up the wholes square & streets yet much of the procession near lost to us.

In 2007, Princeton University Art Museum bought Rubens Peale's Still Life With Watermelon, in honor of John Wilmerding.