DescriptionFirst Day Covers Commemorating the Centennial Anniversary of Millburn Township. Postmarked May 31, 1957 and stamped Last Day & Hour of Cancellation. Second copy has "Helen Jacobus, Postmistress, Millburn, N.ew Jersey" written on it. Commemoration image features Mill (Bill Smith's Mill) and the newly constructed Millburn High School Building with the slogan "A Century of Township Progress."