Cornelius Gilliam was an American politician and military officer known for his role in the early history of the state of Oregon. He served as a member of the Oregon Territorial Legislature and was influential in the establishment of local governance in the region during the mid-19th century. Gilliam was also a prominent figure in the Oregon Trail migration, helping settlers navigate the challenges of westward expansion. His contributions to the community and leadership in various capacities made him a notable figure in the development of Oregon as a state.