Harry Truman actually said...
And I urge Federal, State, and local officials and patriotic, civic, and educational organizations to plan and hold, on or about May 19, exercise designated to help our new citizens, both native-born and naturalized, to understand more fully the significance and responsibilities of citizenship in our self-governing Republic
Context
Proclamation 2680—'I Am an American Day,' 1946
03/11/1946