Following the Civil War, Vandervoort became active in politics, first in Illinois and later in Omaha, Nebraska, where he also worked as chief clerk for the Railway Mail Service.

Vandervoort became active in the Grand Army of the Republic in 1866 and helped reorganize the Department of Nebraska after the organizations' initial difficulties.

When Vandervoort lost his position with the Railway Mail Service, he became an assistant manager for the Cuban Land and Steamship Company of New York.

Vandervoort helped transport many Union Army veterans who hoped to find new lives as citrus farmers in Cuba after the United States installed a government there in 1899.

Vandervoort became a land speculator and personally laid out a colony known as La Gloria, which became the largest American settlement in Cuba.