New Eagle is a borough in Washington County, Pennsylvania, United States and is part of the Pittsburgh Metro Area. The population was 2,047 at the 2020 census. New Eagle, originally called Riverview, adjoins the City of Monongahela and was laid out in 1901 by J. S. Markell in Carroll Township and incorporated as the Borough of New Eagle on Septem…New Eagle is a borough in Washington County, Pennsylvania, United States and is part of the Pittsburgh Metro Area. The population was 2,047 at the 2020 census. New Eagle, originally called Riverview, adjoins the City of Monongahela and was laid out in 1901 by J. S. Markell in Carroll Township and incorporated as the Borough of New Eagle on September 9, 1912. New Eagle is the birthplace of Pro Football Hall of Fame quarterback Joe Montana.