Abe Lincoln's Union Suit?
Contrary to the image depicted here, Honest Abe and his four boys most likely did not wear Union Suits but rather two-piece long underwear. Like most men and boys in the early to mid 19th century, Abe and his sons probably wore separate long-handled, ankle length "drawers" and long sleeved undershirts. Although Union Suits could have been made by wives and mothers on an individual basis in Lincoln's time, Mary Todd Lincoln probably did not have or take time to sew Union Suits for the five males in her famous family.
Some believe that "Union Suits" became popular and got the name because Union soldiers, from drummer boys to generals, wore this type of long underwear in Civil War times. But not likely. Union Suits, drawers and undershirts combined into one garment, were not mass manufactured in the United States until the 1870's, after Lincoln's time.
The one-piece underwear which buttons up the entire front of the suit and with a buttoned flap in the rear became very popular with men and boys beginning in about 1880. Union Suits, of course, are still popularly worn by men and boys today including me.