Complex sentence: In that same year a meeting in Stillwater, later known as the "Stillwater Convention," was held to discuss establishing a new territory, and the participants elected Henry Sibley as a representative to Congress.
Split into simpler sentences: In that same year a meeting, which would come to be known as the "Stillwater Convention," was held in Stillwater with the goal of establishing a new territory. The participants elected Henry Sibley as a representative to Congress.