Leavitt was born in
Lowell, Massachusetts to Erasmus Darwin Leavitt Sr., a native of
Cornish, New Hampshire, and Almina (Fay) Leavitt. He graduated from local schools at age 16, and performed a 3-year apprenticeship at the Lowell Manufacturing Company. After his apprenticeship Leavitt worked for one year at the engineering firm of Corliss & Nightingale in
Providence, Rhode Island before returning to Boston, where he became assistant foreman for Harrison Loring. In this role he designed the
steam engine for the USS
Hartford. From 1859–61 he again worked in Providence, this time as chief draftsman for Thurston, Gardner & Company, builders of steam engines. During the
Civil War, Leavitt first served aboard the USS
Sagamore, then in construction roles in
Baltimore,
Boston, and
Brooklyn, and ultimately as an instructor in steam engineering at the
United States Naval Academy. In 1867 he resigned his teaching post to become a consulting engineer. Leavitt was a member of the
American Academy of Arts and Sciences, and a founding member of the
American Society of Mechanical Engineers, for which he served as vice president from 1881 to 1882, and
president in 1883. In 1884 he received the first honorary doctorate of engineering degree granted by the
Stevens Institute of Technology. Leavitt was a resident of
Cambridge, Massachusetts. He and his wife, the former Elizabeth Pettit, daughter of Philadelphia locomotive designer William Pettit, had five children: Mary Alford; Hart Hooker; Margaret Almira; Harriet Sherman; and Annie Louise. The astronomer
Henrietta Swan Leavitt was his niece. == Work ==