President Obama has issued a proclamation declaring this Thursday as National Day of Prayer.

In his proclamation, he states that prayer has long been an important part of U.S. history. The nation upholds as fundamental principles the exercise of religion and freedom of conscience, he said. Thus Americans have long considered it “fitting and proper” to publicly observe the importance of prayer on May 6.

“On this day, let us give thanks for the many blessings God has bestowed upon our Nation,” said Obama in the proclamation. “Let us rejoice for the blessing of freedom both to believe and to live our beliefs, and for the many other freedoms and opportunities that bring us together as one Nation.”

The National Day of Prayer was officially created in 1952 by a joint resolution of the U.S. Congress, and signed into law by President Harry Truman. Since 1952, every president has signed a National Day of Prayer proclamation.

In April, however, federal judge Barbara Crabb ruled that the National Day of Prayer was unconstitutional because it amounts to a call for religious action. Crabb ruled in favor of Freedom From Religion Foundation, a Wisconsin-based group of atheists and agnostics, that filed the lawsuit in October 2008.

FFRF had originally filed the lawsuit against President George W. Bush and Dana Perino, his press secretary, among others. But the lawsuit has since been changed so that President Obama and Robert Gibbs are among the defendants.

The Obama administration said it intends to appeal Crabb’s decision.

Crabb said her ruling will not bar National Day of Prayer activities until all appeals have been exhausted.

Besides the court ruling, the day of prayer has also been caught in another controversy involving one of its spokespersons.

Evangelist Franklin Graham, co-honorary chair of the National Day of Prayer Task Force, was disinvited from the Pentagon’s National Day of Prayer event over previous comments he made about Islam.

The Council on American-Islamic Relations tried to also get Graham's invitation for the Capitol Hill prayer event rescinded. But congressional sponsors of the event refused to withdraw the invitation for Graham to speak at the prayer gathering at the Capitol.

Graham said he briefly spoke President Obama about being dropped from the Pentagon event when the president recently visited Billy Graham’s home. Obama told him he “would look into it,” Graham said.

For this year’s National Day of Prayer, Obama calls on Americans to particularly remember in their prayers the natural disasters in Haiti and Chile; the families of the West Virginia miners; the people of Poland who have lost many of their country’s leaders; and for those serving in the military.