The first one that comes to mind is the Woolworth's Lunch Counter sit in in Greensboro, North Carolina, in 1960. 4 African American gentlemen walked in and sat down and politely asked for service. They were rudely refused and told to leave. At that point they chose to remain seated. Despite having numerous insults hurled at them, they never fought back nor did they return the hate-filled speech. There are numerous other attempts during the 1950s, where African American men and women attempted to start a change at Soda Fountains around the country.
Jackie Robinson's career is another example of nonviolent protest. He was extremely talented, but one of the main reasons that was cited, as to why he was chosen, was for his ability to control himself. Despite the death threats off the field and the dirty tricks and plays on the field, Robinson never "lost his cool." He gained fans as they watched what he endured on the field.