The 1944-S Threepence was struck by the San Francisco Mint with a total mintage of 32,000,000. San Francisco was the only mint to produce Australian Threepence in this year, unlike the previous two years which were also struck in Denver and Melbourne. The piece features a small 'S' mint-mark under the right-most ribbon on the reverse. This type is very affordable into mint-state with MS65 examples generally available below $100 but anything graded higher can prove quite challenging.
The very large mintage of threepence produced between 1942 and 1944 was a response against a major shortage of both silver and copper coinage. One of the key reasons for this shortage was the mass arrival of United States soldiers into Australia from the Middle East theatre. These troops, along with a general increase in public spending, created an unprecedented demand for coinage. The Melbourne and Perth Mint simply could not make supply match demand so a deal was struck with the United States. Under President Roosevelt's Lend-Lease Policy the United States agreed to provide Australia with a substantial quantity of silver coins. Australia guaranteed to then return an equal amount of silver after the war.
President Theodore Roosevelt had created the extensive Lend-Lease Policy in 1941 as a way to assist allied forces during the Second World War. The program allowed the United States to provide war materials including but not limited to ammunition, aeroplanes, and food that could then be repaid for "...in kind or property, or any other direct or indirect benefit which the President deems satisfactory." The program proved essential to the allied war effort with the total value of the aid reaching $49,100,000,000. (Encyclopaedia Britannica, 2017)
