It's hard to answer this question without more specifics. For example, the ideals of America are often seen to be "liberty and justice for all", as well as the famous quote from the Declaration of Independence that all men are created equal. However, at the time the Declaration was written, many colonies kept slaves, who were obviously not considered free or equal. There have been plenty of other forms of discrimination - against women, Native Americans, Asian Americans, LGBT people, etc. - but civil rights activists have long sought to make America into a place where people can enjoy liberty, justice, and equality regardless of their race, gender, sexual orientation, and so on.