Conservative websites on Tuesday expressed outraged after President Barack Obama read an original version of President Lincoln's Gettysburg Address, which did not include the words "under God."

In celebration of the 150th anniversary of the Gettysburg Address, filmmaker Ken Burns asked dozens of public figures to read the speech.

According to Media Matters, Burns specifically asked the president to read from the "Nicolay Version," which was written before the phrase "under God" was added:

"It is rather for us, the living, we here be dedicated to the great task remaining before us - that, from these honored dead we take increased devotion to that cause for which they here, gave the last full measure of devotion - that we here highly resolve these dead shall not have died in vain; that the nation, shall have a new birth of freedom, and that government of the people, by the people, for the people, shall not perish from the earth."

The phrase, however, was changed slightly by the time the speech was delivered by Lincoln: "that this nation, under God, shall have a new birth of freedom."

By Tuesday morning, the news had become one of the top stories on conservative websites like the Drudge Report, The Daily Caller, the National Review Online and WMAL. The Daily Caller did eventually correct their report to note that Burns had requested the "Nicolay Version" of the speech.

For weeks, conservatives have both been attacking the president for not attending a commemoration ceremony at Gettysburg and saying that he shouldn't attend at all.

Wall Street Journal columnist Daniel Henninger told Fox News host Brian Kilmeade on Tuesday that Lincoln had set out to unify the country and Obama should not attend the commemoration because he was dividing the country.

"The thing that Lincoln said at the Gettysburg Address is that they were gathered there for what he called unfinished business, and the unfinished business was the Civil War, the liberation of the slaves," Henninger explained. "And I remarked that the ascendancy of Barack Obama to the presidency in 2008 was in many ways completing the circle of Lincoln's unfinished business. But at the same time that Gettysburg Address was about unifying the country, the Civil War he had fought to bring the country together."

"It seemed to me if Obama came under those circumstances and spoke about unifying the country, it would not sit well with half the country, who so disagrees with him," he added.

But Henninger also seemed unsatisfied with Obama's decision not to speak because he said it was "unconceivable that the president would not have taken the opportunity to talk about a president he so admired on this special day."

Watch this video from Fox News, broadcast Nov. 19, 2013.

Watch this video from Ken Burns, uploaded Nov. 9, 2013.