Many consider this to be the first true baseball card in that it was produced in large quantities (relative to the cabinets and carte de visites of the era) and offered to firms wishing to place their advertising on the back. The 3-15/16" x 2-3/8" card features a sepia team photo on front of baseball’s first real professional team, including Hall of Famers George and Harry Wright. The Peck & Snyder ad back is the most commonly found, but others are known, including a back which lists only the team’s line-up.