The War of 1812 began on JUNE 18, 1812.
The British captured American ships and enslaved sailors.
They incited Indians to capture Fort Mims, massacring 500 men, women and children. They captured the Capitol, burnt the White House, bombarded Fort McHenry and attacked New Orleans. Outraged, many volunteered for the Army, including Davy Crockett.
In his Proclamation of War, President James Madison stated:
"I do moreover exhort all the good people of the United States...as they feel the wrongs which have forced on them the last resort of injured nations...to consult the best means under the blessing of Divine Providence of abridging its calamities."
In the three years of the War, President Madison, who had introduced the First Amendment in the First Session of Congress, issued Proclamations of Public Humiliation and Prayer in 1812 and 1813, followed by a Proclamation of Public Fasting in 1814, in which he stated:
"in the present time of public calamity and war a day may be...observed by the people of the United States as a day of public humiliation and fasting and of prayer to Almighty God."
After the War, in 1815, James Madison proclaimed a National Day of Thanksgiving to the "Divine Author of Every Good and Perfect Gift."