For his final assault on the Pole, Peary and 23 men, including Ross Gilmore Marvin, set off from New York City on July 6, 1908 aboard the SS Roosevelt under the command of Captain Robert Bartlett. They wintered near Cape Sheridan on Ellesmere Island, and from Ellesmere departed for the pole on February 28 – March 1, 1909. The last support party was turned back from "Bartlett Camp" on April 1, 1909, in latitude no greater than 87°45' north. (The figure commonly given, 87°47', is based upon Bartlett's slight miscomputation of the distance of a single Sumner line from the pole.) On the final stage of the journey toward the North Pole, Peary told Bartlett to stay behind. He continued with five assistants, none capable of making navigation observations: American Matthew Henson, and Inuit Ootah, Egigingwah, Seegloo and Ooqueah. On April 6, 1909, he established "Camp Jesup" allegedly within 5 miles (8.0 km) of the pole.