| Adin Ballou Underwood | |
| Birth Date: | 19 May 1828 |
| Birth Place: | Milford, Massachusetts |
| Death Place: | Boston, Massachusetts |
| Placeofburial: | Newton, Massachusetts |
| Placeofburial Label: | Place of burial |
| Alma Mater: | Brown University |
| Allegiance: | United States of America |
| Branch: | Union Army |
| Rank: | Brigadier General Brevet Major General |
| Unit: | 2nd Massachusetts Infantry Regiment |
| Battles: | American Civil War |
| Laterwork: | Lawyer, Customs Surveyor |
Adin Ballou Underwood (May 19, 1828 – January 24, 1888) was a general in the Union Army during the American Civil War.
Underwood was born in Milford, Massachusetts, on May 19, 1828. He studied law at Brown University, attended Harvard Law School and spent a year in Prussia. When the civil war began he practiced law in Boston. He was commissioned as Captain in the 2nd Massachusetts Infantry Regiment. In 1862 he joined the new 33rd Massachusetts Infantry Regiment as a Major and served in that unit; eventually becoming its Colonel in April 1863.[1]
After the Gettysburg Campaign the XI Corps, of which the regiment was part of, transferred to the west.
On October 29, at the Battle of Wauhatchie, Underwood was shot in the thigh and crippled for life. He still was promoted to Brigadier General in November. The wound healed slowly and when he returned to duty in 1865 he was medically unfit for field service, instead doing court-martial duty.[2] In August 1865 he was brevetted to Major General and mustered out of the U.S. Volunteers. Returning to Boston; he served as surveyor of the port and practiced law again. Underwood died there on January 24, 1888.[3]