What key events and dates signal the beginning and end of the era of colonization?

The era of colonization or simply known as colonialism started in the 16th century and end on the mid of 20th century.

In the 16th century, during the age of discovery, colonialism started when Portugal and Spain started discovering new lands across the ocean. Both empires conquered large extension of lands.

And it ended in the mid 20th century when the US set up the Special Committee on Decolonization in 1962.