William was the third of four children born to William (1737-1798) and Sarah Sloan (1737-1797) Bement. William married (1) Deborah Nichols (1775-1812) about 1790, and there were six children from this marriage. Her burial site has not been discovered at present. After her death in 1812 (age 36), he married (2) Jane Parks Bement (1777-1827) in 1814. No children were born to this marriage. During the early part of his first marriage, William lived in Salisbury, Connecticut. By January 21, 1803 he was in Hudson, then Poughkeepsie, New York. Following that, he lived in Albany, running the American Hotel; his eldest son took over for him there.