The historical conclusion of the British Invasion is ambiguous. American bands regained mainstream prominence in the late 1960s, and along with it, the wave of anglophilia largely faded as American culture shifted in response to the Vietnam War and the resulting civil unrest. Nevertheless, British bands retained their popularity throughout the decade and into the 1970s. British progressive rock acts of the 1970s were often more popular in the United States than their native Britain, as the American working class was generally favorable to the virtuosity of progressive rock acts while the bands' British audience was confined to the more genteel upper classes.