Starting with the big boom, the 1950's began to explore science fiction as a booming trend brought in by the space age. Isaac Asimov wrote "I, Robot" back in that time.
A second social trend that began to develop was the recovery from WWII and our status as an American superpower. We had to anchor ourselves in our conservative values to strengthen our self love and patriotism. For this reason we see books like "Life is Worth Living" by Sheen (Bishop Fulton J) and Ayn Rand in "Atlas, Shrugged".
The 60's reflected the tensions developing in society and this is where we find titles such as "Catch 22", "One Flew Over the Coo-koos Nest" and Harper Lee's "To Kill a Mockingbird".
Women movements were also mirrored in literature with works from Maya Angelou, Sylvia Plath and Gloria Steinem.
The 70's literature reflected a preocupation with egocentrism and spiritualism. This is the decade where we see the book "Im OK, You're OK" (Thomas Harris), and authors such as John Updike, Kurt Vonnegcut, and Toni Morris offer their most deepest writings.
The 80s were the "American reading years" as new and exciting fiction appeared in the works of John Le Carre. Danielle Steele, Tom Clancy, and Alice Walker
Finally, the 90's were the pioneers of online reading, and bookclubs were the major trend. Multiculturalism, autobiographies, celebriality, and current trends were the most seen books in the 90s'
Hope this helps!