A surgical instrument , comprising: a first jaw ; a second jaw , wherein said second jaw is movable relative to said first jaw between an open position and a closed position, and wherein said second jaw comprises: a proximal end ; a distal end; a pivot rotatably connecting said proximal end to said first jaw; a tissue compression surface extending between said proximal end and said distal end; a first cam surface positioned proximally with respect to said pivot, wherein said first cam surface extends at a first angle relative to said tissue compression surface; and a second cam surface positioned proximally with respect to said first cam surface, wherein said second cam surface extends at a second angle relative to said tissue compression surface, and wherein said second angle is different than said first angle; and a closure drive configured to move said second jaw into said closed position, wherein said closure drive comprises a rotary drive screw and a closure cam operably coupled to said rotary drive screw, wherein said closure cam is driven proximally by said rotary drive screw when said rotary drive screw is rotated in a first direction, wherein said closure cam is driven distally by said rotary drive screw when said rotary drive screw is rotated in a second direction, wherein said closure cam is configured to contact said first cam surface during a first portion of a closure stroke and then said second cam surface during a second portion of said closure stroke to move said second jaw into said closed position, and wherein, for a given speed of said closure cam, said closure cam drives said second jaw toward said first jaw at a faster rate during said first portion of said closure stroke than said second portion. a first jaw ; a second jaw , wherein said second jaw is movable relative to said first jaw between an open position and a closed position, and wherein said second jaw comprises: a proximal end ; a distal end; a pivot rotatably connecting said proximal end to said first jaw; a tissue compression surface extending between said proximal end and said distal end; a first cam surface positioned proximally with respect to said pivot, wherein said first cam surface extends at a first angle relative to said tissue compression surface; and a second cam surface positioned proximally with respect to said first cam surface, a proximal end ; a distal end; a pivot rotatably connecting said proximal end to said first jaw; a tissue compression surface extending between said proximal end and said distal end; a first cam surface positioned proximally with respect to said pivot, wherein said first cam surface extends at a first angle relative to said tissue compression surface; and a second cam surface positioned proximally with respect to said first cam surface, wherein said second cam surface extends at a second angle relative to said tissue compression surface, and wherein said second angle is different than said first angle; and a closure drive configured to move said second jaw into said closed position, wherein said closure drive comprises a rotary drive screw and a closure cam operably coupled to said rotary drive screw, wherein said closure cam is driven proximally by said rotary drive screw when said rotary drive screw is rotated in a first direction, wherein said closure cam is driven distally by said rotary drive screw when said rotary drive screw is rotated in a second direction, wherein said closure cam is configured to contact said first cam surface during a first portion of a closure stroke and then said second cam surface during a second portion of said closure stroke to move said second jaw into said closed position, and wherein, for a given speed of said closure cam, said closure cam drives said second jaw toward said first jaw at a faster rate during said first portion of said closure stroke than said second portion. <EOS>