He enlisted in the 44th Massachusetts Infantry Regiment in 1862 and served in the Department of North Carolina for six months during the American Civil War.
[5] After Thomas Russell resigned as Collector of Customs for the Port of Boston, Benjamin Butler lobbied for Simmons to get the job.
George Frisbie Hoar wrote that the "National executive patronage in Massachusetts seemed given up to advancing the personal fortunes of General Butler" and that Simmons' nomination excited a "deep indignation".
[7] However, The Boston Globe also reported that the majority of dispatches received by Senators George S. Boutwell and Charles Sumner were in favor of Simmons.
[1] After leaving office, Simmons worked in the manufacturing and mining businesses, helped found the Boston Evening Star, and served as president of the Massachusetts Benefit Life Association.
[10] An investigative committee chaired by alderman Thomas N. Hart found that Simmons knew that the land could have been purchased for less and had received profits from the sale.
He was involved in mining and real estate in New York for a time and in 1896 moved to Chicago, where he was an agent and representative of the Clark Thread Company.