[1] Edward O. Leech was a direct lineal descendant of Lawrence Leach (1589–1662), a follower of Francis Higginson who settled in Salem, Massachusetts in 1629; Edward O. Leech's great-grandfather, Captain Hezekiah Leach fought in the French and Indian War and the American Revolutionary War.

[1] On the death of Leech's father in 1869, he became a clerk in the Bureau of Statistics of the United States Department of the Treasury.

[3] Upon retiring from government service, Leech became Vice President of the National Union Bank in New York City.

[4] At the 1896 Republican National Convention, Leech played a major role in securing a plank in the party's platform favorable to maintaining the gold standard.

[4] Leech died of complications related to appendicitis at Mount Sinai Hospital in New York on May 1, 1900.