Bar examination
Uanna worked for private companies as well as the US Army Corps of Engineers. As a civilian with the Corps of Engineers he was involved in the construction of Grenier Army Air Field in New Hampshire and Fort Devens in Massachusetts, where he later served as an Army Counter Intelligence agent during World War II. Between 1938 and 1942 he attended Suffolk University, graduating with an L.L.B. He then passed the Massachusetts Bar examination and was admitted to practice before the Federal Bar. Between 1949 and 1954 he attended the American University in Washington, D.C.