The DoI said that all men are "created equal, with certain inalienable rights, and among these are life, liberty, and the pursuit of happiness." This laid the foundation that the US was supposed to be a free and equal society.
In reality however, African Americans remained in slavery until the civil war. Also, women were unable to vote until the late 1900s. Clearly, the ideals and values outlined in the DoI were very different from the realities of daily life for women and African Americans during early American history.