[1] He was born in Brimfield, Massachusetts, where he spent his early years helping his father Morris Burke Belknap (the elder) (1780–1877) in an iron furnace foundry business.

[4][5] He became a prominent Kentucky citizen and businessman who hosted Ulysses S. Grant and William T. Sherman in his home during the American Civil War.

[7]During the period of the American Civil War, William Burke Belknap owned and resided in a house subsequently occupied by the Pendennis Club.

The twins were both born on February 25, 1925, and both were killed in action while serving in the U.S. Army in 1944 during the World War II defense of Normandy, France, thus leaving Lily a widow with no living children or parents.

He was the great-great-grandfather of economist Thomas MacGillivray Humphrey and of Barbara Morgan Meade, a founder and former co-owner of Politics and Prose book store in Chevy Chase, Washington, D.C. W. B. Belknap, also known as William Burke Belknap (the elder), was the great-great-grandfather of John Lawrance Hawkes, who edited and published in 2000 the journal of Joel Root, Hawkes' ancestor who kept a log of his journey around the world on a sailing ship seal hunting expedition which departed from New Haven, Connecticut on September 1, 1802.