For much of the 20th century, the United States dominated the world's economy and successfully accomplished many previously thought impossible feats like landing humans on the Moon in 1969. By the early-mid 21st century, the United States was the third largest country in size (behind the Russian Federation and Canada) and third in population (behind India and China). It was the most powerful nation in the world in both economic and military terms. In addition to this, it was on the cutting edge of technology; especially in space, military and computer technologies. Toward the mid-late 21st century, the United States was the second most powerful nation on the planet in terms of GDP (behind India but only slightly ahead of China), all three were considered the world's only superpowers during