He was an early American designer and advocate of sewer systems that keep domestic sewage separate from storm runoff.

[4] At the beginning of the American Civil War, Waring resigned from the Central Park project to accept a military commission as major.

He departed New York in the early summer, and drilled for a month in Washington DC, occasionally meeting President Lincoln as he reviewed the troops.

Waring acquired a new charger, Ruby, a chestnut described as "a picture of the most abject misery; his hind legs drawn under him; the immense muscles of his hips lying flabby, like a cart-horse’s; his head hanging to the level of his knees, and his under-lip drooping; his eyes half shut, and his long ears falling out sidewise like a sleepy mule’s.

[2] During the 18th century, merchants of Newport, Rhode Island, developed country agricultural estates in the outlying towns.

[8][9] Sanitary conditions in the city were poor, with many domestic wells close by privies and drained by a fetid bayou.

Civic leaders recognized the need for better drainage and a sewer system that would keep domestic waste away from the wells, although they were wrong in their belief that yellow fever was spread by inadequate sanitation practices.

The financially strapped city and the state legislature were unable to raise sufficient funds for construction of a conventional combined sewer system, due to the mass exodus of residents for fear of yellow fever.

Garbage piles reached a foot or two deep,[13][14] cleared only haphazardly by "ragtag army of the unemployed.

"[13] Waring began by securing a law requiring horses and carts to be stabled overnight, instead of being left on the street.

[2] Waring was married three times: first in 1855 to Euphemia Johnston Blunt; second in 1865 to Virginia Clark; and third on July 20, 1898, to Louise Yates of New Orleans.

[citation needed] Soon after his third marriage, while in Cuba Waring contracted yellow fever and died shortly after returning to New York City on October 29, 1898.