In 1937 the Sinclair Refining Company launched a major promotional campaign with Babe Ruth as its principal spokesperson. In addition to a twice-weekly radio show starring Ruth, the promotion also featured a weekly essay contest for kids that offered hundreds of prizes, including Ruth-signed baseballs. Offered here is one of those prize balls, complete with both its original retail box and shipping box. The official National League (Frick) ball bears a "Sinclair Babe Ruth Baseball Contest" label on the opposite sweet spot and is inscribed "Sincerely Babe Ruth" on a side panel in black ink. It has long been established in the hobby that these Babe Ruth Sinclair prize balls were not actually signed by Babe Ruth but instead display a "secretarial" signature. This was not done maliciously at the time, but was probably necessary due to the large number of prize balls (500) given away each week. The ball displays light toning and soiling, and is in Excellent condition overall. The original Spalding retail box is in Fair to Good condition, with creases and small tears throughout. The original mailing box (3.25 x 3.25 x 3.25 inches), addressed to "Mr. C. W. Humphrey" of St. Paul, Minnesota, displays moderate wear and tape repair to one seam. In Good condition overall. Total: 3 items (ball, retail box, and mailing box). Reserve $200. Estimate (open).