1. The first recorded Valentine's Day celebration in Ohio occurred in 1786 when a group of frontiersmen west of Marietta held a dance in honor of the holiday.

2. In 1824, Ohio's state legislature declared Valentine's Day a holiday. However, the holiday was later removed from the state calendar in 1855 due to concerns over Catholic influence.

3. The Cincinnati Zoo, founded in 1875, hosts an annual Valentine's Day event called "Valentine's Day with the Animals." Visitors can watch as the zoo animals receive special Valentine's Day treats.

4. Ohio is home to the world's largest collection of Valentine's Day cards and memorabilia. The collection is housed at the Miami University Art Museum in Oxford, Ohio and includes over 20,000 items dating back to the 1840s.

5. In 1971, the Ohio National Guard was deployed to the Ohio State Penitentiary in Columbus after a riot broke out on Valentine's Day. The riot lasted 11 days and resulted in the deaths of 10 inmates and one guard.