There is provided a surgical stapler having a staple formation recognition system incorporated into an anvil member of the surgical stapler. In one series of embodiments, a trace system and controller form an open electrical circuit and a surgical staple (70) acts as an electrical connector to complete an electrical circuit and confirm the proper formation of the surgical staple. In another series of embodiments, a trace system and a controller form a complete electrical circuit which is broken by engagement of a surgical staple with a trace pad of the trace system to signal proper formation of the surgical staple. There is also provided a knife blade position indication system for tracking the progress of a knife blade through the anvil member and relative to staple crimping pockets formed in the anvil member.