A surgical instrument for stapling the tissue of a patient is disclosed. The surgical instrument comprises a shaft and an end effector. The end effector comprises a staple cartridge body including staple cavities defined therein, staples removably positioned in the staple cavities, an anvil configured to deform the staples, and a knife configured to cut tissue positioned intermediate the staple cartridge body and the anvil. The surgical instrument further comprises a staple drive system configured to eject the staples from the staple cavities and a knife drive system configured to move the knife relative to the staple cartridge body independently of the staple drive system.