Career
He also established the landmark line of "White Ace" stamp albums. ArtCraft became one of the world"s most popular cachets. In 1939 they established the Washington Press, which created and sold White Ace album pages for collectors.
They also printed and sold high-quality envelopes bearing an Artcraft (later "ArtCraft") cachet of each anticipated United States stamp to be issued, so that stamp collectors could have the envelope franked and canceled by the post office with a “first day of issue” cancellation.
He also helped create interest for the hobby of first day covers by instituting awards at various stamp shows and exhibitions. Leo was a benefactor of the Smithsonian Institution’s National Postal Museum in Washington, District of Columbia and American Philatelic Society in Bellefonte, Pennsylvania, and one of the founders of the Cardinal Spellman Philatelic Museum on the campus of Regis College in Weston, Massachusetts.
The Leo and Samuel August Memorial Award for best topical first day cover exhibit is given on an annual basis by the American First Day Cover Society. And, in his will, Leo provided a large bequest to The American Philatelic Research Library.