Protection of an individuals "mode of worship" was enhanced beyond the protections afforded by the Amendments to the Constitution of the United States of America.
On August 7, 1789, President George Washington signed the Northwest Ordinance of 1789 into law after the newly created U.S. Congress reaffirmed the Ordinance with slight modifications under the Constitution. The Ordinance purported to be not merely legislation that could later be amended by Congress, but rather "the following articles shall be considered as Articles of compact between the original States and the people and states in the said territory, and forever remain unalterable, unless by common consent...."
Art. I. No person, demeaning himself in a peaceable and orderly manner, shall ever be molested on account of his mode of worship or religious sentiments, in the said territory
A Century of Lawmaking for a New Nation: U.S. Congressional Documents and Debates, 1774 - 1875 Statutes at Large, 1st Congress, 1st Session
For further research on the North-West Ordinance SEE: http://en.wikipedia.org/wiki/Northwest_Ordinance