1829-33: John Ross, from England, and his nephew James discover the magnetic North Pole on the Island of Somerset.

1820: The American, Nathaniel Palmer, becomes the first European to have seen the Antarctic.

1838: The American, Charles Wilkes, discovers Wilkes Land.

1886: The American, Robert Peary, explores the ice sheet of Greenland.

1906: Roald Amundsen, from Norway, becomes the first man to reach the South Pole.

1908: The American, Vilhjalmur Stefansson explores the Canadian Arctic.

1909: The American, Matthew Henson, plants the American flag near the North Pole.

1914: The American, Robert Bartlett, reaches Siberia.

1956: Final expedition of the American Richard Byrd in the Arctic.