The American Cowboy can be found on the second floor of the Clothing Store and purchased for 32 Bucks. Purchasing this hat will allow you to wear this hat only in Adopt Me!, unless you buy this item from the Roblox Catalog.
The description of this item on the Roblox Catalog reads
"...or Cowgirl! You know how to rope in some lookieloos to your America place. Yee haw! Rating prize for the July 4, 2010 Building Contest."