Throughout the rest of the war, relations between Kennedy and the Roosevelt Administration remained tense, especially when Joe Jr. vocally opposed President Roosevelt's unprecedented nomination for a third term, which began in 1941. Kennedy may have wanted to run for president himself in 1940 or later. Having effectively removed himself from the national stage, Joe Sr. sat out World War II on the sidelines. Kennedy stayed active in the smaller venues of rallying Irish-American and Roman Catholic Democrats to vote for Roosevelt's re-election for a fourth term in 1944. Former Ambassador Kennedy claimed to be eager to help the war effort, but as a result of his previous gaffes, he was neither trusted nor invited to do so.  Due to his philanthropy and a close friendship with Francis Spellman, Archbishop of New York (later Cardinal), during this time, Joseph Kennedy was invested as a knight of the Sovereign Military Order of Malta, an honor which at that time he shared with just a few dozen Americans.  With his ambitions to achieve the White House no longer viable, Joe Kennedy held out great hope for his eldest son, Joseph P. Kennedy Jr., to seek the presidency. However, Joe Jr., who had become a U.S. Navy bomber pilot, was killed over the English Channel in 1944 while undertaking Operation Anvil, a high-risk, new way to use heavy bombers to strike German weapon sites in France. The intention was to use remote-controlled aircraft from which the pilot had bailed out after a piloted take-off. Joe Jr's bomber exploded before he and his co-pilot could bail out.  After grieving over his dead son, Joe Sr. turned his attention to his second son, John, for a run for the presidency. After serving as a member of the House of Representatives beginning in 1946, and then a U.S. Senator beginning in 1952, the younger Kennedy entered the Presidential election in 1960, and won it.

Answer this question "Did Joe Sr. do anything important outside of politics during this time?" by extracting the answer from the text above.
Joseph Kennedy was invested as a knight of the Sovereign Military Order of Malta, an honor which at that time he shared with just a few dozen Americans.