1. The Great Dayton Flood: On May 10, 1913, a devastating flood struck the city of Dayton, Ohio. Over the course of three days, the city received between 6 and 11 inches of rain, causing the Great Miami River to overflow its banks and inundate much of the city. The flood caused widespread damage and loss of life, with over 400 people killed and more than 20,000 left homeless.

2. The Creation of Mothers' Day: May 10, 1908, marked the first official observance of Mothers' Day in the United States. The holiday was created by Anna Jarvis, a resident of Grafton, West Virginia, who wanted to honor her own mother and promote the idea of honoring mothers nationwide. The first Mothers' Day celebration took place at a church in Grafton, and the holiday quickly caught on around the country.

3. The Birth of James Ritty: James Ritty, the inventor of the first cash register, was born on May 10, 1836, in Dayton, Ohio. Ritty's invention, which he called the "Incorruptible Cashier," was patented in 1879 and revolutionized the retail industry by providing an accurate and secure way to track cash transactions.

4. The Assassination of William McKinley: On September 6, 1901, President William McKinley was shot by anarchist Leon Czolgosz at the Pan-American Exposition in Buffalo, New York. McKinley died of his wounds on September 14, and his vice president, Theodore Roosevelt, was sworn in as president. However, the events of McKinley's assassination had a significant impact on the state of Ohio, where he had been governor prior to his presidency and where he remains a beloved figure to this day.

5. The Founding of Cleveland: On July 22, 1796, a group of surveyors arrived on the banks of the Cuyahoga River and began laying out the city of Cleveland. The settlement quickly grew into a bustling commercial center, thanks in large part to its location on Lake Erie and the opening of the Ohio and Erie Canal in 1832. Today, Cleveland is the second-largest city in Ohio and a major hub for industry, healthcare, and culture in the region.