Thousands of Americans are expected to participate today's National Day of Prayer, which a U.S. appeals court approved earlier this year after it was ruled unconstitutional in 2010.
Organized by the National Day of Prayer Task Force, more than 35,000 people are expected to gather across the country in prayer, according to the group's website.
The National Day of Prayer was created in 1952 by Congress and signed into law by Harry Truman. A federal judge's ruling in 2010 that it was unconstitutional was struck down earlier this year by a U.S. appeals court, the Christian Science Monitor reported on April 14.
President Obama issued a proclamation designating May 5 as a National Day of Prayer on April 29. He issued similar proclamations in 2009 and 2010.
"Today the president will join millions of Americans in personal prayer to mark this important day," a White House spokesperson, Shin Inouye, told msnbc.com.
The National Day of Prayer Task Force's chairperson is Shirley Dobson, the wife James Dobson, founder of Focus on the Family and considered by some to be the country's most influential evangelical leader.