The Association for the Sciences of Limnology and Oceanography (ASLO) traces its roots to the Limnological Society of America (LSA), which was established in 1936 to further interest and research in limnological science. The society was an outgrowth of the meetings and discussions of the National Research Council's Committee on Aquaculture during the previous decade (Lauff, G.H. 1963. A history of the American Society of Limnology and Oceanography. Pp. 667-682 in, (D.G. Frey, ed.) Limnology in North America. University of Wisconsin Press, Madison).
While the LSA had members working in both freshwater and marine systems, the name did not reflect this until 1948 when the Oceanographic Society of the Pacific merged with the LSA to become the American Society of Limnology and Oceanography. ASLO is incorporated as a non-stock (non-profit) corporation in the State of Wisconsin.
Membership in the society has grown from 221 LSA charter members in 1936 to roughly 3500 ASLO members today, of whom 1400 are now drawn from countries other than the United States. In 2011, ASLO members voted to change its name to the Association for the Sciences of Limnology and Oceanography, reflecting the increasingly international nature of the society.
For more information about the early history of ASLO, read the fascinating 1998 L&O Bulletin article written by Daniel Conley on the 50th anniversary of the founding of ASLO.
The merger of limnology and Oceanography within ASLO: A historical perspective (open access)