This stamp was announced by the USPS on March 6th:
First established during the Revolutionary War as the American colonies fought for independence, the U.S. Navy is now at the forefront of cutting-edge technology that safeguards the maritime interests of the United States, ensuring economic prosperity and the freedom of the seas. Featuring the emblem of the Navy against a white background, this stamp celebrates the U.S. Navy’s 250th anniversary. Antonio Alcalá, an art director for USPS, designed the stamp.
No date of issuance or city was given. The latest information will appear below the line, with the most recent at the top.