John Cadwalader (1742–1786) was the son of Dr. Thomas Cadwalader and Hannah Lambert Cadwalader. He and his brother Lambert were Philadelphia businessmen.

On 18, 19, and 20 May an important series of races was run in Philadelphia, which GW and Jacky Custis almost surely attended, although there is no mention of it in the diaries. The races were run under the auspices of the Jockey Club and were among the most important social events of the year in Philadelphia. Governor Eden had entered his bay horse, Why-Not, in the Jockey Club Purse, the first and richest of the races, but the race was won by Israel Waters’s horse, King Herod (Pa. Chronicle, 24 May 1773; HARRISON [3] description begins Fairfax Harrison. Early American Turf-Stock, 1730–1830. 2 vols. Richmond, Va., 1934–35. description ends , 2:117–18).