Here are five historical events that happened in Delaware on April 30:

1. In 1788, Delaware became the first state to ratify the United States Constitution.

2. In 1909, the Delaware State Fair Association was founded in Harrington, Delaware.

3. In 1947, the Delaware Memorial Bridge was opened to the public, connecting Delaware and New Jersey.

4. In 1967, Swedish diplomat and Secretary-General of the United Nations, Dag Hammarskjöld's plane crashed near Ndola, Zambia, killing him and 15 others. Hammarskjöld was originally from Jönköping, Sweden, but spent part of his childhood in Wilmington, Delaware.

5. In 1988, Delaware Governor Michael N. Castle signed into law a bill that made Delaware the first state to outlaw discrimination based on genetic testing. The law prohibited employers, insurers, and other entities from using genetic tests to deny service, employment, or coverage, and was considered a landmark piece of legislation at the time.