During the Age of imperialism the US abandon some of is democratic ideals in order to obtain colonies and territories and become a world power.
One of the one they abandoned was equality. "White Mans Burden" was the theory that the native people from colonies the US had were uncivilized and inferior, and believed that they needed to be educated and civilized.
Another ideal the US abandoned was truth. After being promised their independence and not getting it the people of the Philippines revolted causing the Philippine-American War.
The US did not abandon all their democratic ideals. The common good was an ideal that America didn't abandon. For example Teddy Roosevelt helped Panama gain their independence from Colombia so they could build the Panama Canal which was important for shipping and the economy.