What is a specific event/person that had a major impact on American life on which I could write a thesis paper?

This movement/event/person needs to be from the 20th century onwards, and could have affected American life politically, socially, economically. I was thinking of doing something with the Civil Rights Movement, but it is too broad a subject.What is a specific event/person that had a major impact on American life on which I could write a thesis paper?
On May 4, l970 members of the Ohio National Guard fired into a crowd of Kent State University demonstrators, killing four and wounding nine Kent State students. The impact of the shootings was dramatic. The event triggered a nationwide student strike that forced hundreds of colleges and universities to close. H. R. Haldeman, a top aide to President Richard Nixon, suggests the shootings had a direct impact on national politics. In The Ends of Power, Haldeman (1978) states that the shootings at Kent State began the slide into Watergate, eventually destroying the Nixon administration. Beyond the direct effects of the May 4th, the shootings have certainly come to symbolize the deep political and social divisions that so sharply divided the country during the Vietnam War era.What is a specific event/person that had a major impact on American life on which I could write a thesis paper?
You're right on that, waaaay to broad.



the development of the transistor.

first landing on the moon.

Lindbergh's flight across the Atlantic.

FDR, as in Pres. Roosevelt.

Mrs. Roosevelt.

Kennedy

Jackie.

Prince.

The Beatles, but that's almost as bad as the CRM.

Tearing down the Berlin Wall

Building the Berlin Wall.

The Camp David Accord.



...that outta get cha started.