sentences:  Both sides agreed that the disputed Chamizal strip connecting El Paso to Ciudad Juárez would be considered neutral territory with no flags present during the summit, but the meeting focused attention on this territory and resulted in assassination threats and other serious security concerns.The Texas Rangers, 4,000 U.S. and Mexican troops, U.S. Secret Service agents, BOI agents (later FBI) and U.S. marshals were all called in to provide security.An additional 250 private security detail led by Frederick Russell Burnham, the celebrated scout, was hired by John Hays Hammond, a close friend of Taft from Yale and a former candidate for U.S. vice president in 1908 who, along with his business partner Burnham, held considerable mining interests in Mexico.