State Representative Mike McGhee sponsored the amendment in the state legislature.
"That it is okay for people to have prayer in public as long as they don't disturb other people around them," he said.
State Representative Jeannette Mott Oxford opposed the amendment, saying it's already covered by the first amendment to the U.S. Constitution.
"Our religious freedom is so precious, it's settled for all time. It doesn't need to go to a vote. If we put it on a ballot, that cheapens the Bill of Rights."
Polling showed the proposed state amendment drawing more than 80 percent support.
The U.S. Constitution protects the right to pray in public places, but supporters for the amendment wanted to reaffirm those rights.
Last May, Governor Jay Nixon signed a proclamation to put the proposed amendment on the August ballot.
Under the amendment, "...any person shall have the right to pray individually or corporately in a private or public setting so long as such prayer does not result in disturbance of the peace or disruption of a public meeting or assembly..."
"You really can't have too many restraints on the freedom of religion," said Rep. Charlie Norr (D-132 District). He says this part of the Missouri Constitution is acceptable, but the new amendment will cover more ground. "I believe it was adequate before, but this does expand it and make it more accessible to schools."
The amendment reaffirms that students can privately pray in public schools, but it would not allow schools to hold class prayers.
Some voters believe their child shouldn't be denied this right.
"I'd come unglued" said Linda Saggese. "I really would."
"That's our constitutional right as far as I know public place or private place," said Patty Lane.
Another addition of the amendment says,"...all free public schools receiving state appropriations shall display, in a conspicuous and legible manner, the text of the bill of rights of the constitution."
"I think it's a good section explaining the Bill of Rights," added Norr. "Sometimes opponents didn't like the idea, but it is part of the constitution and I believe the children in school should be aware of the Bill of Rights."
The amendment also says students can express religious beliefs in assignments, free from discrimination.
The measure will have no impact on taxes.