Every fourth Thursday in November, people in the United States gather with family and loved ones around tables overflowing with food and drink to celebrate Thanksgiving.

The holiday is a moment to give thanks and spend time with relatives and friends, and it is steeped in traditions. Holiday décor — with images of autumn leaves, cornucopias and turkeys decorating seasonal napkins, plates and centerpieces — brightens homes and dining tables. Extra chairs are hauled up from the basement to accommodate extended family. A sense of celebration and joy hangs in the air, as relatives who might not see each other often reunite for the day. They eat a plentiful meal, watch football and parades, and then eat even more. Thanksgiving is one of the nation's most widely celebrated secular holidays. Schools, banks, government offices and most businesses close for the day as people travel from near and far to be with their families.