Right whales were named by whalers who identified them as the "right" whale to kill on a hunt. These leviathans had enormous value for their plentiful oil and baleen, which were used for corsets, buggy whips, and other contrivances. Because of their thick blubber, right whales also float accommodatingly after they have been killed. Populations of these whales were decimated during the whaling heydays of the 17th, 18th, and 19th centuries. During this period they came close to extinction. All species of right whales are endangered and have enjoyed complete international protection since 1949. Northern right whales are the most endangered of all large whales. They number only several hundred, and populations do not appear to have grown in the decades since their protection began.