Rhode Island Tercentenary Issue First Day Cover
300th Anniversary of the Settlement of Rhode Island
Issued on May 4, 1936 in Providence, RI - Scott #777

Unofficial Town Cancel - Longmeadow, RI
John Kilton Cachet - Planty #777-61i

The Longmeadow Post Office, (Warwick Township, Kent County) was established on October 3, 1903 under Postmaster Charles H. Poland. The Post Office was disestablished on June 30, 1949 and mail is handled through the Warwick Post office. 
(This Post Office was originally known as the Bayside Post Office, which was established on October 11, 1897 under Postmaster Florence Read. The name was changed to Longmeadow in 1903.)

Sources:
Check List of Rhode Island Post Offices 1790-1994 - Del Beaudreau
Rhode Island Postal History: The Post Offices - Merolla, Jackson & Crowther