kjdelapaz kjdelapaz 04-04-2018 History contestada How did US involvement in Vietnam change over time? - check all that apply - * The United States sent more and more troops to Vietnam in the 1960s. * The United States turned over defense of South Vietnam to the South Vietnamese army. * The United States took over the defense of South Vietnam. * The Gulf of Tonkin Incident led the United States to declare war on North Vietnam. * The Gulf of Tonkin Resolution gave the president more authority to get involved in Vietnam.