Think the first Thanksgiving was celebrated by pilgrims and Native Americans? Think again. Despite what Wednesday Addams and company would have you believe, the real roots of the holiday are a lot more political.While pilgrims did celebrate feasts of thanksgiving — at more or less whatever time they felt particularly thankful — the holiday only gained official status during the Civil War, when President Abraham Lincoln declared it a national celebration. In 1863, with the Civil War still raging, an elderly magazine editor wrote to President Lincoln and encouraged him to make the festival official nationwide.Lincoln, ever conscious of the morale of a nation at war, took the suggestion. His proclamation declared that the last Thursday of November to be a day of Thanksgiving for “the whole American People.” The proclamation, issued in early October, also referenced a “humble penitence for our national perverseness and disobedience.”But that’s not the end of the holiday’s history as a political tool. In 1939, as the Great Depression had the entire country in turmoil, President Franklin D. Roosevelt grabbed hold of the holiday as a way to help boost the economy. Intead of the usual four, November of that year had five Thursdays. But instead of celebrating on the final Thursday, the 30th, FDR declared that Thanksgiving would actually be celebrated on the fourth, the 23rd. Why? Unlike today, when Christmas decorations go on sale the moment the jack-o’-lanterns go out, in 1939, most people didn’t begin their Christmas shopping until after Thanksgiving. With the economy in collapse, the government wanted to encourage shoppers to spend more, earlier, and longer. Apparently, calendar makers weren’t so happy about it. They printed their wares in advance and ended up having to throw away a whole year of stock.So when you’re carving up the turkey and someone decides to bring up their thoughts on economic policy, let them go for it. Politics, like strange can-shaped cranberry sauce, has always been a part of the festivities.