A surgical stapling instrument comprising an end effector is disclosed. The end effector comprises an anvil and a cartridge jaw comprising a channel. A staple cartridge is replaceably seated in the channel. The staple cartridge comprises a longitudinal slot extending from a proximal end toward a distal end, a first longitudinal row of staple cavities extending alongside the longitudinal slot, and second and third longitudinal rows of staple cavities extending alongside the first longitudinal row. Staples are removably positioned in the staple cavities. A double staple driver supports a staple from the first row and a staple from the second row. A single staple driver supports a staple from the third row. A sled comprises first and second camming surfaces configured to drive the double staple driver and the single staple driver toward the anvil, respectively. Distal ends of the first and second camming surfaces are staggered.