County sheriffs. Which is to say, if you enter a contract with me, breach it, and get a judgment entered against you, it will ultimately be the county sheriff w

County sheriffs. Which is to say, if you enter a contract with me, breach it, and get a judgment entered against you, it will ultimately be the county sheriff who will come execute the judgment on your property, sell it at auction, and give the proceeds to me. The federal government is not likely to take a significant role except if I get the judgment from a federal court or the property is someplace very weird.