1. Maine becomes a state: The most significant event in Maine's history that happened on May 2 is the state's admission to the Union. In 1820, President James Monroe signed a bill that officially granted Maine statehood, making it the 23rd state in the United States.

2. The Battle of Frankfort: One of the smaller battles during the Civil War, the Battle of Frankfort took place on May 2, 1863. The Confederates, led by General John Hunt Morgan, attacked the Union forces stationed in Frankfort, Maine, in an attempt to capture the state capitol. Although the Confederates were eventually repelled, the battle led to the deaths of several soldiers on both sides.

3. The Great Fire of Sanford: On May 2, 1903, a raging fire broke out in the town of Sanford, Maine, destroying much of the downtown area. The fire caused over $1 million in damages and completely destroyed several buildings, including the town hall and the library.

4. The Maine State Prison riot: In 1973, a violent and deadly riot broke out at the Maine State Prison in Thomaston, Maine. The riots were sparked by the overcrowding, poor conditions, and tensions between prisoners and guards. The riot began on May 2 and lasted until May 8, resulting in the deaths of two inmates and several injuries.

5. Mount Katahdin is designated as a national park: On May 2, 1903, Maine’s largest mountain, Mount Katahdin, was designated as a national park, becoming the first state park east of the Mississippi River. The park, which is located in Baxter State Park, is a popular destination for outdoor enthusiasts and hikers.