Over the past century, The American Legion has grown into the largest veterans' organization in the United States, with over 10,000 volunteer posts nationwide.

Paris Post 1 has also played a pivotal role in ISP's history. In 1964, Monique Porter opened the doors of Pershing Hall School with a small 'Junior Primary Class' of just eight children, including her daughter, Caroline. The school was supported by the American Legion and by Caroline's father, Russell Porter, a former Commander of Paris Post 1 and the President of the Pershing Hall Operating Committee (PHOC) at the time. ISP's first home was in Pershing Hall, which also housed the headquarters for Paris Post 1. This landmark American memorial building has deep historical ties, connecting France to an international Anglophone community.