23mm, General Staff Officer button with the eagle grasping arrows in the left talon. " Robinsons, Jones & Co/Makers/Attleborough/Mass."  Rare and unusual backmark.  This early(!) staff button could have gone to Mexico during the Mexican War.  McGuinn and Bazelon do not even record it on a U. S. Staff button in their book, American Military Button Makers and Dealers; Their Backmarks & Dates.