Complex sentence: George Simpson Governor-in-Chief of the HBC paid Smith $2,600 for the horses and furs and in return, Smith assured that his American fur trade company would confine its operations to the region east of the Great Divide.
Split into simpler sentences: George Simpson Governor-in-Chief of the HBC paid Smith $2,600 for the horses and furs. In return, Smith assured that his American fur trade company would confine its operations to the region east of the Great Divide.