The graph shows labor union membership. A graph titled Labor Union Membership in the U S from 1930 to 2000 has years on the x-axis and percentage of employed workers on the y-axis from 0 to 40 percent in increments of 10. Membership was lowest in 1930 and peaked around 1945. During what years did union membership peak? in 1945 and 1955 in 1960 and 1970 in 1930 and 1950 in 1965 and 1970