The following was taken from the CIA World Factbook:
The US took possession of the island in 1857, and its guano deposits were mined by US and British companies during the second half of the 19th century. In 1935, a short-lived attempt at colonization began on this island but was disrupted by World War II and thereafter abandoned. The island was established as a National Wildlife Refuge in 1974.
A simple map of Baker Island. Courtesy of the CIA.