John Alexander Ahl
Member of the U.S. House of Representatives from Pennsylvania's 16th district
In office March 4, 1857 – March 3, 1859
Preceded by	Lemuel Todd
Succeeded by	Benjamin F. Junkin
Personal details
Born	(1813-08-16)August 16, 1813 Strasburg, Pennsylvania
Died	April 25, 1882(1882-04-25) (aged 68) Newville, Pennsylvania
Political party	Democratic
Alma mater	University of Maryland
Signature

John Alexander Ahl (August 16, 1813 – April 25, 1882) was a surgeon, real estate developer, paper mill and iron furnace operator, railroad executive and United States Congressman from Pennsylvania. He was born in Strasburg, Pennsylvania in 1813.

Ahl studied medicine at the University of Maryland, and graduated in 1832. He moved to Centerville, Pennsylvania, where he practiced medicine through 1856. That year, he began in the real estate business, bought a paper mill in Newville, Pennsylvania, and served as a delegate to the 1856 Democratic National Convention in Cincinnati.

He was elected to the United States House of Representatives in 1857, leaving upon the completion of his first term.

After Congress, he manufactured paper and operated an iron furnace in Sharpsburg, Maryland. He also served as the planner and the major builder of the Harrisburg and Potomac Railroad.

He died in Newville in 1882, and is buried in Big Spring Presbyterian Cemetery.

• Who Was Who in America: Historical Volume, 1607-1896. Chicago: Marquis Who's Who, 1963.
• The Political Graveyard

• United States Congress. "John Alexander Ahl (id: A000060)". Biographical Directory of the United States Congress.