Why was new york times v. sullivan (1964) significance?

The Court ruled that free debate allows people to publish ads, otherwise, they would be too scared to air their own opinion. *Established the Sullivan Test: you can sue for libel if the information is false and the newspaper knew it was false but decided to intentionally publish it

Primary sources are usually  more accurate and are written by someone who experienced it or witnessed it. secondary sources are those who heard of it after the fact that can lose details and or twist the event in a light that benefits them.