This Lincoln writing calls the last, maybe the first, national day of fasting for the US. It was called for April 30, 1863 when we were dealing with civil war. (It was the only one I could find about fasting.)
1775: The first day of prayer was declared when the Continental Congress “designated a time for prayer in forming a new nation.”
1795-FEB-19: George Washington proclaimed a day of public thanksgiving and prayer.
Circa 1813: President James Madison proclaimed a day of prayer. He later said such proclamations are not appropriate. “They seem to imply and certainly nourish the erroneous idea of a national religion.”
1808: Thomas Jefferson also opposed declarations of national days of prayer by the Federal government. He wrote “Fasting and prayer are religious exercises; the enjoining them an act of discipline. Every religious society has a right to determine for itself the time for these exercises, and the objects proper for them, according to their own particular tenets; and right can never be safer than in their hands, where the Constitution has deposited it.”
1863-MAR-30: Abraham Lincoln signed a Congressional resolution of MAR-3 which called for a day of fasting and prayer.
1952-APR-17: A bill proclaiming a National Day of Prayer (NDP) was unanimously passed by congress. President Truman signed it into law. It required the President to select a day for national prayer each year.