You should send your completed “Application for Naturalization” (Form N-400) to the
appropriate USCIS Lockbox Facility that serves your area.
I few things to remember. Make a complete copy of your entire file which includes anything you send to Immigration Services. Do not send any original documents with your application unless an original is especifically required and asked for.
If you reside in Florida, your application must be filed in Dallas, Texas, P.O. Box 660060, Zip code 75266.