Many offices and some businesses will be closed Monday. The federal holiday of Columbus Day is observed on the second Monday of October each year. Closures include banks and post offices. The United States Postal Service will not deliver mail on Monday. It became a federal holiday in the United States in 1937. Some states and cities have replaced the day with Indigenous Peoples’ Day, including Tama and Toledo in Iowa. Last year, Governor Kim Reynolds proclaimed the day as Iowa inaugural Indigenous Peoples Day.