The National Day of Prayer shares common roots with the celebration of Thanksgiving; both were national proclamations establishing a day of prayer. In the New England Colonies under British rule, traditional observances in late fall called for prayer and thanksgiving, while observances in the spring or summer called for prayer and fasting. The fall observance was established by President Abraham Lincoln as the official Thanksgiving holiday in 1863. The spring observance was established by President Harry S. Truman in 1952 as the National Day of Prayer.