Keeler was the son of Burr Bradley Keeler (b. Aug. 1, 1844), a Rochester, New York-born real estate owner; grandson of Rufus Keeler and Phoebe Valeau; great-grandson of Josiah Keeler and Betsey Bradley; and a descendant of Sons of the American Revolution-registered Isaac Keeler (b.1715), Lieutenant of the 5th Connecticut Regiment, and his wife, Hannah Stebbins; Josiah Keeler (b. Jan. 22, 1741-1777), a private in the 5th Connecticut Regiment, and his wife, Elizabeth Stebbins; and Philip Burr Bradley (March 26, 1738-Jan. 24, 1821), Colonel of the 5th Regiment of the American Army, and his wife, Ruth Smith.