His failure to mention slavery in a proclamation of April as Confederate History Month was "a major omission," Virginia's Republican governor said on Wednesday.

Gov. Bob McDonnell had come under fire for the proclamation honoring those who fought for the South in the U. S. Civil War. He initally defended it, saying it was designed to promote tourism in Virginia.

The Washington Post has reported that McDonnell issued a statement Wednesday apologizing for failing to "include any reference to slavery" and calling that a mistake.

McDonnell said, "The proclamation issued by this Office designating April as Confederate History Month contained a major omission. The failure to include any reference to slavery was a mistake, and for that I apologize to any fellow Virginian who has been offended or disappointed."

Next year will mark the 150th anniversary of the start of the Civil War in 1861.

The commonwealth's two previous Democratic governors both refused to issue the mostly symbolic proclamation honoring the men who fought for Virginia.

Virginians are called by the seven-paragraph declaration to "understand the sacrifices of the Confederate leaders, soldiers and citizens during the period of the Civil War."

It has been called an insult to a large segment of Virginia's population by the Virginia NAACP and the state's Legislative Black Caucus.

McDonnell called slavery "an evil, vicious and inhumane practice which degraded human beings to property and … left a stain on the soul of this state and nation."

McDonnell further said "The abomination of slavery divided our nation, deprived people of their God-given inalienable rights, and led to the Civil War." (With Inputs from Agencies)