After noticing Illinois did not have a state flag on display while visiting Continental Memorial Hall in Washington D.C., Ella Park Lawrence, then the State Regent of the Daughters of the American Revolution, began lobbying the Illinois General Assembly to adopt an official state flag.

On July 6, 1915, the Great Seal on a white background became Illinois’ official state flag. The flag was modified in 1970, including the word “ILLINOIS” under the seal to ensure those unfamiliar with the seal knew the flag was the official state flag of Illinois.

Learn more:
Illinois State Flag – Illinois Secretary of State
Illinois State Flag – 50States.com