AMERICAN CHEMICAL SOCIETY MEMBERSHIP: Sold growth faltered only during Depression of 1930s and recession to early 1970s

ACS membership has grown at an average annual rate of 3.2% since 1923. Growth was strongest from the later years of the Depression through the early post-World War II years, with an average 9.2% annual gain from 1935 through 1951. The longest pause in growth came in the 1970s. Membership dropped from nearly 117,000 in 1969 to about 110,000 between 1972 and 1975 and did not move ahead of the 1969 level until 1979.