In spite of his Quaker blood he had a great fondness for a military life, and on his return to New York he entered West Point, but abandoned this in deference to his father's wishes.

On his return to Marseilles he was offered and accepted a position with a firm in that city, and during 1845 he was sent by them to Turkey, Greece, Piedmont, Italy, and Austria.

He was one of the founders of the Bellevue Medical College, where he at one time held the chair of surgical anatomy, and was professor of clinical and operative surgery from 1872 until his death.

[1] On the outbreak of the American Civil War he was given two hours' notice to proceed to Washington, D.C., with the first regiments of New York Militia on April 18, 1861.

In 1864–65 he was medical inspector of the Department of Virginia, with headquarters with the Army of the James, under Major-General Edward Ord, and served under him until the war was at an end.

Mott was present at the interview between Generals Robert E. Lee and U.S. Grant on the occasion of the signing of the agreement of surrender at Appomattox Court House, Virginia.

[1] His father, Valentine Mott, possessed the qualities that made him famous for his operations; he was almost as dexterous with one hand as with the other, and to a great extent the son inherited his skill.