Duane's take
Here's how the official marker tells it, and I'll do my best to do it justice. Hamilton County. Created February 2, 1842, carved right out of Montgomery and Houston counties.
Now, you'd think that would be the end of the origin story, but Texas being Texas, the county had to be recreated on January 22, 1858, and then organized on August 2 of that same year. Some things just need a second try to take root properly. The county carries the name of General James Hamilton, born in 1786 and gone by 1857.
And what a name to carry. Hamilton was a lawyer, a Governor of South Carolina, and a man of enough standing that President Lamar appointed him diplomatic agent to Europe. Lawyer, governor, diplomat.
The kind of resume that makes you wonder when the man ever slept. The county seat bears his name too, Hamilton, sitting right there at the heart of the county that honors him. One man's name on the land, on the town, on the road signs you pass without a second thought, until somebody like me slows down long enough to tell you who he was.
What the marker says
Created February 2, 1842 from Montgomery and Houston counties; recreated January 22, 1858, organized August 2, 1858. Named in honor of General James Hamilton, 1786-1857. Lawyer and Governor of South Carolina; appointed diplomatic agent to Europe by President Lamar. Hamilton, the county seat.