Educated at home, Seward became interested in finance and later started a partnership with Clinton McDougall, was private secretary to his father, then a U.S.

[1][2] A few weeks after Seward's promotion to colonel, his regiment was sent north to meet the threat to Washington, D.C. posed by Confederate Lieutenant General Jubal Early's Valley Campaigns of 1864.

[1][2][3] He was promoted to brigadier general on September 13, 1864, and in January 1865 was assigned to command a brigade in the Department of West Virginia, which he did until April 1865.

Seward commanded the 3rd Division for 6 days after Confederate partisan rangers captured Brigadier General George Crook on February 20, 1865.

[4] In 1886, he was elected as a companion of the New York Commandery of the Military Order of the Loyal Legion of the United States and was assigned insignia number 4696.