Fold3 is an online archive for U.S. military records.
The documents in this collection include full pension application files for soldiers and sailors who served in the War of 1812, as well as for their widows and children, or other heirs. The first applications were filed by servicemen who were disabled as a result of their service, or by widows who lost a husband in the war.
The descriptive pamphlet for the Index to War of 1812 Pension Application Files, M313, published by NARA, provides a great deal of background and explanatory information about the pension files and the acts that provided for them.
So far 65% of this collection has been indexed. The War of 1812 Pension Files at Fold3 is currently accessible at no charge.