With a single industry specific exception in Illinois, there is no state where 15 minute rest breaks are required. There are a few states, not including North Dakota, where ten minute rest breaks for every four hours worked is required, but only SOME hotel workers in Illinois have a legal expectation of 15 minute breaks.
The only break required by law in North Dakota is a 30 minute break, unpaid (if the employee is entirely relieved of duty) for each shift of over 5 hours. It does not apply if only one employee is on duty.