Career
He served on and off in the New York National Guard from 1893 onwards and enlisted in the federal army in 1917. Lefferts spent most of his time outside of the military studying uniforms of the American Revolution. A self-taught artist, he recorded his meticulous research efforts by making many illustrations of uniforms used by all of the forces involved in the war and also by collection illustrations made by other artists.
Three years after his death, the society published many of his images and their descriptions in a book titled Uniforms of the Armies in the War of the American Revolution, 1775-1783.