Seleem Choudhury originally from England, right, and his son Oliver, 2, was born in States are in Civic Center park for a Naturalization ceremony celebrating new citizens on Thursday. Seleem and a diverse group of 503 area residents representing 86 countries took the Oath of Allegiance and become U. S. citizens during a special naturalization ceremony at the Civic Center. The ceremony is part a series of naturalization ceremonies held throughout the country to celebrate Citizenship Day, which is celebrated Sept. 17 in remembrance of the signing of the Constitution in 1787.