Born in Hackensack, New Jersey, Cassedy attended the common schools, where he studied law. He was admitted to the bar in 1809 and commenced practice in Hackensack, and became the postmaster of Hackensack from June 10, 1805, to January 1, 1806.
Cassedy was elected as a Democratic-Republican to the Seventeenth Congress, reelected as a Jacksonian Democratic-Republican to the Eighteenth Congress, and reelected as a Jacksonian to the Nineteenth Congress (March 4, 1821 – March 3, 1827). He died in Hackensack, December 31, 1842, and was interred there in the First Reformed Dutch Church Cemetery.
- United States Congress. "George Cassedy (id: C000234)". Biographical Directory of the United States Congress.
- George Cassedy at The Political Graveyard
- George Cassedy at Find a Grave
|U.S. House of Representatives|
| Member of the U.S. House of Representatives
from New Jersey's at-large congressional district
March 4, 1821 – March 3, 1827