Curious Bounty Land Assignment in Illinois

In the early days of the blog, almost a year ago, I wrote about my third-great-grandfather John O'Brien, who may or may not have served in the US Navy during the War of 1812. While I have not gotten closer to resolving that mystery, I have taken a close look at an assignment of a bounty land warrant in LaSalle County, Illinois that I am hoping will shed some light on John O'Brien's arrival in Illinois.

40 acres bounty land
On 10 October 1853, James A Booth assigned his 40 acre bounty land warrant #66521 to John O'Brien. The land was located in LaSalle County, Township 036 North, Range 002E, SW 1/4 NE 1/4, Section 27. Booth had been a private in Captain Bush's Company, Georgia Militia. It's hard to read, but below that line are the words "Florida War". This is pretty interesting. The Florida War would have been the Seminole Wars. It would help to know who Captain Bush was, and more about the company that served in this war.

Three other bounty land warrants were executed for Section 27 in LaSalle County on 10 October 1853. All of them were to men who had served in the War of 1812, not the Florida War.

Additional information would help quite a bit. I cannot find John O'Brien in the census in LaSalle County in 1860, and I know that he and family had moved to Shelby County by about 1861.