A surgical stapler, comprising: a handle assembly; an end effector coupled to the handle assembly, the end effector including: a first jaw member including a plurality of surgical staples; and a second jaw member including an anvil portion, at least one of the first jaw member or the second jaw member is moveable relative to one another between an open position and a clamped position; a firing rod disposed in mechanical cooperation with the end effector; a drive motor coupled to the firing rod, the drive motor configured to advance the firing rod to cause the first and second jaw members to clamp tissue and to eject the surgical staples; one or more sensors (185,187,189) configured to measure a clamping force exerted on tissue by the first and second jaw members (164,162) and to measure a firing force of the surgical staples; and a controller (405,500) operatively coupled to the drive motor and configured to control a speed of the drive motor based on the measured clamping force, wherein the controller (405,500) is configured to perform the following steps: determine an initial clamping force based on measurements received from the one or more sensors (185,187,189), the initial clamping force being determined when a predetermined time period has elapsed following clamping of tissue between the first and second jaw members (164,162); control the speed of the drive motor to initiate firing of the staples at an initial firing speed dependent on the initial clamping force; and throughout the firing of the staples, continually monitor and determine the firing force of the staples and control the speed of the drive motor to adjust the firing speed based on the continually monitored firing force. a handle assembly; an end effector coupled to the handle assembly, the end effector including: a first jaw member including a plurality of surgical staples; and a second jaw member including an anvil portion, at least one of the first jaw member or the second jaw member is moveable relative to one another between an open position and a clamped position; a first jaw member including a plurality of surgical staples; and a second jaw member including an anvil portion, at least one of the first jaw member or the second jaw member is moveable relative to one another between an open position and a clamped position; a firing rod disposed in mechanical cooperation with the end effector; a drive motor coupled to the firing rod, the drive motor configured to advance the firing rod to cause the first and second jaw members to clamp tissue and to eject the surgical staples; one or more sensors (185,187,189) configured to measure a clamping force exerted on tissue by the first and second jaw members (164,162) and to measure a firing force of the surgical staples; and a controller (405,500) operatively coupled to the drive motor and configured to control a speed of the drive motor based on the measured clamping force, wherein the controller (405,500) is configured to perform the following steps: determine an initial clamping force based on measurements received from the one or more sensors (185,187,189), the initial clamping force being determined when a predetermined time period has elapsed following clamping of tissue between the first and second jaw members (164,162); control the speed of the drive motor to initiate firing of the staples at an initial firing speed dependent on the initial clamping force; and throughout the firing of the staples, continually monitor and determine the firing force of the staples and control the speed of the drive motor to adjust the firing speed based on the continually monitored firing force.