P's car was stopped waiting to turn onto U.S. Highway 63. Mailboxes obscured his view of traffic. Believing the road was clear, P started onto the highway. A pickup truck broadsided his vehicle, causing serious injuries. Before the collision, the county sheriff and a deputy - residents near where P's car was stopped - complained to the Postmaster about the location of the mailboxes. The deputy sheriff presented the Postmaster a petition, signed by many residents, requesting they be moved. The Postmaster refused, citing the extra cost. After P's injuries, the USPS received letters and another petition. The relocation of the mailboxes was then approved. P sued D, alleging that the USPS negligently placed, maintained, and failed to relocate the mailboxes. The district court found sovereign immunity applied, and thus it lacked subject matter jurisdiction. P appealed.