1941-1970

The successive threat and actuality of war replaced the Depression as a threat to undergraduate operations of Alpha Sigma Phi. The bombing of Pearl Harbor on December 7, 1941 was followed by military mobilization, carrying most able-bodied men of college age into the armed forces. After the spring of 1942, college student populations were depleted by the draft, and many chapters had to close for lack of membership. Even Alpha Chapter, which had sparked the rebirth of Alpha Sigma Phi only 36 years prior, closed in 1943. Older alumni became guardians of chapter archives and assets, while houses were rented to universities as dorms or used as civilian and military housing. Executive Secretary Ralph Burns had to take a day job and ran the Fraternity on nights and weekends.

MERGER WITH ALPHA KAPPA PI
By the end of the war, there were only seventeen chapters that had the ability to resume standard operations. The Fraternity was faced with the problem of rebuilding, a task that would require extra staff members and alumni support. Costs had risen since the war had begun, and there was little income flowing into the National Organization. In 1945, there was definitely not enough income to support an office and staff in New York City.

Alpha Kappa Pi was facing an even worse predicament. Alpha Kappa Pi granted thirty-four charters between its establishment between 1921 and 1943, including six chapters absorbed from failing or threatened national fraternities, Sigma Delta Rho and Theta Nu Epsilon. Its chapters were almost exclusively east of the Mississippi River. Between 1926 and 1941, Rev. Wilson served as the administrative officer of Alpha Kappa Pi, operating out of his church offices. At the end of the war, Rev. Wilson retired from the ministry and advised the fraternity that a proper national staff and headquarters would be needed for the organization to continue. In 1946, Alpha Kappa Pi had seventeen operating chapters and was in no financial position to acquire an office and staff. Between the two organizations, Alpha Kappa Pi and Alpha Sigma Phi, however, it was financially feasible to afford an office and staff. The merger was announced at the Alpha Sigma Phi Centennial Convention in Marietta, Ohio and at the Silver Anniversary Convention of Alpha Kappa Pi in Ocean City, New Jersey on September 6, 1946.

MERGER WITH ALPHA GAMMA UPSILON
Four students founded Alpha Gamma Upsilon at Anthony Wayne Institute in Fort Wayne, Indiana during the spring of 1922. The merger of Alpha Gamma Upsilon with Alpha Sigma Phi was a quiet affair. Dr. Otto Sonder, an alumnus of the Beta Chi Chapter of Alpha Sigma Phi at American University, was the faculty advisor for the Alpha Gamma Upsilon Chapter at Lycoming College and was involved in the discussion of the merger. He was well acquainted with the officers of Alpha Gamma Upsilon, Clayton "Sparky" Force and Stuart Anderson. Brother Sonder was also aware of the concern the small fraternity had for its future, and introduced them to Alpha Sigma Phi's Executive Secretary, Ralph F. Burns.

In 1965, the Alpha Gamma Upsilon Chapter at Lycoming was installed as Gamma Rho Chapter of Alpha Sigma Phi. Chapters at Detroit Institute of Technology, Indiana Institute of Technology, and Eastern Michigan University followed in 1966. The four chapters installed in 1964 and 1965 were, under the terms of the merger agreement, deemed chartered in Alpha Sigma Phi as of their chartering dates in Alpha Gamma Upsilon, 1951, 1930, 1932, and 1948, respectively. The merger was not completed, however, until Lawrence Institute of Technology was re-accredited and its 55-year-old Alpha Gamma Upsilon Chapter chartered in 1968. The "Old Gal" gained five chapters from the merger. Unlike the merger with Phi Pi Phi and the consolidation with Alpha Kappa Pi, there was no blanket invitation to Alpha Gamma Upsilon alumni to be initiated into Alpha Sigma Phi, although some of the more prominent leaders of Alpha Gamma Upsilon did so. The Alpha Gamma Upsilon Chapter at General Motors Institute (now Kettering University) did not participate in the merger, but sought and received a charter from another national fraternity.