I'd like to mention that I've read a biography of John D. Rockefeller by Ron Chernow so I am acquainted with the subject. I'd like a more broad view because then I'd like to move on to read about Andrew Carnegie and Cornelius Vanderbilt(I know he died around the 1870s but I think he's a good example of the practices of those times).
And if you have any other suggestions on periods, wars, etc.(those less known) that are especially significant and present interesting and important ideas and concepts, I am looking forward to your suggestions.
For a big picture history of the Gilded Age, you can't go wrong with Richard White's recent book The Republic for Which It Stands: The United States during Reconstruction and the Gilded Age, 1865-1896. It's the latest volume in the Oxford History of the United States, a series that has won a number of major awards, including multiple Pulitzers.