1916 Sovereign

Some time after 1916, the US central bank received a large number of 1916 sovereigns as payment from the UK government for services related to WWI. After 1933, when the US went off the gold standard, all gold held by the US government was barred. Many collectors believe that this is how a large quantity of 1916 (and 1917) sovereigns met their fate. Today, the 1916 sovereign is relatively scarce and very difficult to source. An underrated date, in my view.