Our take: Since President Harry S. Truman first declared a National Day of Prayer to be held annually on the first Thursday in May, in 1952, people from many different faiths who believe in the power of prayer have come together to pray for various personal and public needs. In opposition to this, a National Day of Reason has begun for non-believers who want to operate in protest against this long-held tradition.

Americans marked the National Day of Prayer Thursday (May 3), with Christians gathering on Capitol Hill to defend their right to pray as nonbelievers observed a Day of Reason.

Shirley Dobson, wife of Focus on the Family founder James Dobson and the chairwoman of the National Day of Prayer Task Force, said the total of 40,000 observances across the U.S. for the National Day of Prayer "belies the fact of many skeptics saying that citizens in our nation no longer believe in prayer.

The American Humanist Association used Thursday to mark the National Day of Reason, and encouraged atheists, agnostics and nonbelievers to give blood or participate in counter demonstrations.

Read more about the National Day of Reason on The Washington Post.