Speaker of the House 1849-1851; also a commissioned colonel in the Civil War...
You looked up the wrong Cobb.
Cobb County was named for Thomas Willis Cobb (1784 – February 1, 1830) a United States Representative and Senator from Georgia.He was elected to the Senate to fill the vacancy caused by the death of Nicholas Ware and served from December 6, 1824 until his resignation in 1828. He was a judge of the superior court of Georgia, and died in Greensboro in 1830. Cobb County, Georgia is named in his honor, the county seat of Marietta is named for his wife Mary.
They probably should have named it for Peter Kolb. At least he lived there.
https://www.nps.gov/stateoftheparks/kemo/culturalresources/kolbfarmhouse.cfm