By 1783 or thereabouts, his business was doing well enough to raise his income above that of the average person in his trade, and tax records throughout the 1780s prove increasing success.
In 1789 he joined the Pennsylvania Abolition Society and was nominated to the Action Committee, where he attended weekly meetings; he remained a member the rest of his life.
He bought a share in the Library Company of Philadelphia, and built up a collection of books evidencing his "rather pedestrian taste" in reading.
[1] Trotter made six mahogany ladderback chairs for the banker and slave owner Stephen Girard in 1786; they are cited as an example of a "more modest" neoclassical style that was making inroads in Philadelphia.
[3] Other chairs that resemble Trotter's are frequently ascribed to him, including two in the collection of the Metropolitan Museum of Art, but those two have details that suggest they are not his.