Providing loans and land grants. The construction and operation of the line was authorized by the Pacific Railroad Acts of 1862 and 1864 during the American Civil War. Congress supported it with 30-year U.S. [ government bonds and extensive land grants of government-owned land. ]
Wheres the wrest of the question?
Because LBJ, under the Tolkien Resolution, was given basically infinite power to protect U.S interests in Vietnam. Thus, President Johnson continued to "escalate", or build up American forces, weapons, and intervention in Vietnam. Now, somewhat opposite of this would be "Vietnamization" under Nixon, which was the gradual withdrawal of American troops but a continuation of supplies in order to aid South Vietnam from the Vietcong.
Both country build up new technology to compete against each other in the race to space thus creating longer range missle.