[1][2][3] Nevius joined the law office of future U.S. Secretary of War Russell A. Alger in Spring 1861.

[1][3] On July 11, 1864, he commanded the center of a small band and led a charge during Early's raids near Fort Stevens in Washington, D.C.

[1] In 1866, Nevius became a Deputy Collector of Internal Revenue for Monmouth County, New Jersey and then worked as an insurance agent in Marlboro.

In 1896, Nevius was appointed by Governor Griggs as Judge of the Circuit Court of Hudson County.

[6] In 1881, Nevius helped organize and served as the commander of the Grand Army of the Republic chapter in Red Bank.

He retired in October 1908 when he was elected the Commander-in-Chief of the Grand Army of the Republic, beating former Minnesota governor Samuel Van Sant.

[1][7] After serving one year as Commander-in-Chief, he returned to his private practice as a counselor-in-law and also worked in a chancery.