Why does the Milky Way have a supermassive black hole called Sagittarius A*?

Sagittarius A* is the compact radio source at the center of our galaxy and is widely accepted as a supermassive black hole. It likely began as a smaller seed black hole or a dense remnant in the early Milky Way and then grew by swallowing gas and merging with other black holes. Over time, the central region of the galaxy provided material that helped it reach about 4 million times the Sun’s mass. Stars near the center orbit extremely fast because of its gravity. The Event Horizon Telescope has also helped confirm the nature of the black holes at galactic centers.