He immigrated to the United States in 1851 where he worked in the merchant industry in Chicago, Illinois, before moving to Camden, New Jersey, in 1860.

He served as an officer in the Union Army during the American Civil War, receiving the Medal of Honor for his actions at the Battle of Chancellorsville.

[2] Sewell began his Civil War service as a captain with the 5th New Jersey Volunteer Infantry on August 28, 1861.

[3][4] On his return he was given command of the 38th New Jersey Volunteer Infantry, but his wounds eventually caused him to end his Civil War field service.

[3] In recognition of Sewell's service, on January 13, 1866, President Andrew Johnson nominated Sewell for appointment to the brevet grade of brigadier general, United States Volunteers for "gallant and meritorious services at the Battle of Chancellorsville, Va.," to rank from March 13, 1865, and the U.S. Senate confirmed the appointment on March 12, 1866.

[5] On July 18, 1868, President Andrew Johnson nominated Sewell for appointment to the brevet grade of major general of volunteers for "gallant and meritorious services during the war," to rank from March 13, 1865 and the U.S. Senate confirmed the appointment on July 23, 1868.

He also was President of the West Jersey & Seashore Rail road Company, a post he held until his death.

Sewell died of complications from heart disease and diabetes at 9:40am on December 27, 1901, at age 66, in his home at Camden, New Jersey.