22. On March 30, 1867, the U.S. purchased Alaska from Russia.

The US purchased Alaska for US$7.2 million, paying less than 2 cents an acre for almost 600,000 square miles.

23. Largest Country in the world by area

Russia is the largest country in the world covering more than a ninth of the Earth’s land area. Russia has a 17-million-square-kilometer surface compared with 16.6-million- square-kilometer surface for Pluto, making this country larger than the largest and second-most-massive known dwarf planet in the Solar System.