Unbeknownst to most Americans, National Religious Freedom Day is celebrated every year on Jan. 16, the anniversary of the adoption of the Statute for Religious Freedom by the Virginia Assembly in 1786.

This legislation, drafted by Thomas Jefferson and guided to passage by James Madison, marked the first time in history that a legislature voted to disestablish religion, preparing the way for the American observation of religious liberty under the First Amendment to the U.S. Constitution.

Each year, Religious Freedom Day comes and goes with little fanfare beyond a pro forma proclamation from...