11 defining moments in Jack Dorsey’s rise and fall at Twitter

Twitter CEO Jack Dorsey changed the world, 140 characters at a time.

The social media platform helped open up the globe, allowing people in all corners to communicate in a public forum. But the site also has its issues, as misinformation has spread rapidly, largely unchecked or monitored too slowly or late.

With Dorsey stepping down from his role, here’s a look at how he got here.

Twitter CEO Jack Dorsey steps down, CTO Parag Agrawal named as replacement »

1999: Dorsey quits New York University and moves to California to start an online company that dispatches taxis, couriers and emergency vehicles.