The National Day of Prayer (36 U.S.C. § 119) is an annual day of observance held on the first Thursday of May, designated by the United States Congress, when people are asked "to turn to God in prayer and meditation". The law formalizing its annual observance was enacted in 1952, and is being challenged in court.
On March 30, 1863, President Abraham Lincoln issued a proclamation expressing the idea "that the awful calamity of civil war, which now desolates the land, may be but a punishment, inflicted upon us, for our presumptuous sins", and designated the day of April 30, 1863 as a day of "national humiliation, fasting and prayer" in the hope that God would respond by restoring "our now divided and suffering Country, to its former happy condition of unity and peace". He went on to say, "...it is the duty of nations as well as of men, to own their dependence upon the overruling power of God, to confess their sins and transgressions, in humble sorrow, yet with assured hope that genuine repentance will lead to mercy and pardon; and to recognize the sublime truth, announced in the Holy Scriptures and proven by all history, that those nations only are blessed whose God is the Lord.