Pike's Expedition Zebulon Pike contributed to westward expansion by gathering about the Louisiana Territory. Summer 1805 (First Expedition) • Pike spent several months exploring and mapping the River. • He purchased Native American lands, which would be used for future US outposts. July 1806 (Second Expedition) • He and a group of volunteers explored the southern Louisiana Territory. • He was asked to build ties with the Native Americans and find out what the were doing at the boundary of the territory. • He and his group entered -held lands where they were and taken to Mexico. • Pike was eventually released and able to return to the US to share his findings.