The Vietnam War cast a long shadow over Nixon’s presidency. Opposition to the war, including the president’s secret bombing campaign of Cambodia, intensified protests that began in the mid-1960s. Environmental demonstrations, such as the first Earth Day on April 22, 1970, were modeled on antiwar and civil-rights protests. High-school students in Denver march in observance of Earth Day, 1970.


The Denver Public Library, Western History Collection, RMN2129.