After Cadwell studied medicine in Vermont, he married a daughter of Matthew Lyon. George Cadwell was born on February 21, 1773, in Wethersfield, Connecticut. Cadwell married Pamelia Lyon, the daughter of Matthew Lyon in 1797.
He helped her father publish The Scourge of Aristocracy and Repository of Important Political Truth, a paper attacking United States. president John Adams.
He attended school in Hartford, Connecticut and then studied medicine in Rutland, Vermont.
He left with Lyon to Kentucky, but then settled in the Indiana Territory after a dispute about slavery. He served in the government of Madison County, then was elected to the Illinois Senate when the state was founded in 1818. He served three two-year terms, then resumed the practice of medicine.
He settled with her family in Fair Haven, Vermont.
The Alien and Sedition Acts forced the family to flee the state, and in 1799, they settled at what is now Eddyville, Kentucky. Messinger and Cadwell left Lyon in 1802 to settle in the Indiana Territory.
Cadwell purchased 200 acres (81 ha) opposite Gaboret Island on the Mississippi River, about 9.5 miles (153 km) north of Cahokia, in what is now Saint Clair County, Illinois. He built a cabin, farmed, and practiced medicine.
Cadwell was appointed a justice of the peace for Saint Clair County on July 9, 1809.
When Madison County, Illinois Territory was created in 1812, which included his farm, Cadwell was named a justice for that county. In August 1813, he was named commissioner of the county court of common pleas, responsible for managing taxes. That December, he was appointed judge of the same court.
The next December, he was appointed Judge of the Madison County Court.
Cadwell then moved to Edwardsville after purchasing land from Thomas Kirkpatrick. After Illinois was admitted as a state in 1818, Cadwell was elected to the 1st Illinois General Assembly as a state senator
In December 1820, he was named President pro tempore of the senate after Lieutenant Governor Pierre Menard requested a leave of absence. He resigned the next month.
He was re-elected in 1820 and moved near what is now Lynnville, at the time still a part of Madison County.
During this session, Greene County, Illinois, was created. Cadwell"s farm now stood in the new county, so he represented it when elected to the next general assembly. He was also considered a representative of the new Pike County.
After the 3rd General Assembly, Cadwell purchased a 240-acre (97 ha) plot of land in Morgan County.
The land was largely timbered and Cadwell harvested sugar and syrup until the 1850s. He platted part of his claim as the town of Quincy, hoping to secure the location of the county seat.
However, the county commissioners instead settled on Jacksonville. Cadwell spent the rest of his practicing medicine as the first physician in Morgan County.
He built the first frame house in the county and created the Morganian Society, an anti-slavery group.
He was named the first postmaster in the county. He died in Morgan County on August 1, 1826 and was buried in Diamond Grove Cemetery in Jacksonville. He was the great-grandfather of state senator Epler Cadwell Mills.
