As students head back to classrooms in Florida, they will see 'In God We Trust' prominently posted on school walls, as it is now 'mandatory.'

'In God We Trust' has been America's national motto since the mid-1950s. It is on our currency and in the halls of Congress. As religious tensions have grown in the U.S., there has been an increased demand for religious liberty. Six states have passed laws in the last year, either allowing or requiring the phrase to be displayed in public schools.

The push for these laws comes from what's called 'Project Blitz,' a campaign sponsored by the Congressional Prayer Caucus Foundation.

Its handbook suggest twenty 'Model Bills' for conservative lawmakers to use. The proposal for displaying 'In God We Trust' is first on the list.

Some critics and parents see the law as a violation of separation of church and state.