Pinkerton Ross Vaughn Sr. (1839 – August 22, 1866) was a United States Marine Corps sergeant who served during the American Civil War.

He was the second Marine to be awarded the Medal of Honor for his actions aboard the USS Mississippi during a battle with Confederate artillery batteries at Port Hudson, Louisiana, on March 14, 1863.

[5] On July 10, 1863, Vaughn was awarded the Medal of Honor (Navy version) for his actions during the night of March 14 aboard the Mississippi.

He was "commended for zeal and courage displayed in the performance of unusual and trying service while the vessel was aground and exposed to a heavy fire".

[8] Vaughn returned home to Pennsylvania after he was discharged, and secured work as a brakeman with a trolley company in Philadelphia.

[11][12][13] The West Chester Village Record reported on his death as follows:[14] Fatal Accident - On Wednesday, the 22nd, while the 3d stock train on the Penna.

rail road was going east, one of the brakemen named Pinkerton R. Vaughn, was struck on the head by an overhead Bridge west of City Avenue, causing death in about 40 minutes.