Columbus did not discover America first, but what he did was to perfect Celestial Navigation methods and record the route so others could follow behind him, and they did.
The impact of these accomplishments was to change the geopolitics of the world forever.
Western Europe changed from the backwater of Eurasia into the center of all trade and navigation in the world. This is why the 0 meridian runs through London, not Istanbul, Mecca or Delhi. Because Western Europeans wrote the navigational charts.
This also cut the economic trade foundation of middle Eastern Countries down to zip-zero-nada and they did not recover until the oil industry came to them and made them rich again.
Columbuses achievements allowed for global trade, and brought new foods to the old world.
Thank Columbus that you can eat tomatoes, watermelon, cucumbers and most other vegetables we have today.
Most of all, Columbus did allow for numerous European kingdoms to allow their dissidents to come to our continent and establish colonies that could experiment with novel forms of government, among them the Pilgrims of New England.