This body of water was central to a dispute resolved in 1927 that resulted in the unusual geographic position of the so-called “Country Club Area.” C. R. Moore (15[1])foiled a double assassination attempt (15[1])in 1909 during a conference that (15[1])involved land adjacent (15[1])to this body of water called Cordova Island. A 1967 discovery (15[1])by James Hill Jr. has allowed over 250 people to successfully claim citizenship due to being born near this body of water on the Horcón (“ohr-KOHN”) Tract. Outside of Bluetown near the mouth of this river sits a historical marker for the (*) Thornton Affair. Its course was partly placed into a concrete channel in the 1960s to resolve the long-running (-5[1])Chamizal dispute. An incident at a city near this river’s mouth resulted in Theodore Roosevelt dishonorably discharging buffalo (-5[1])soldiers who allegedly killed a white (10[1])bartender. For 10 points, Brownsville lies at the mouth of what (-5[1])river which sets the US–Mexico border in Texas? (10[3])■END■