July 4, 1776 - American colonists heard the words of the Declaration of Independence, that "all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."
Find out more about the Declaration at http://www.ushistory.org/declaration/
July 4, 1829 - Frances Wright of Scotland, an early feminist and utopian socialist, was invited by Philadelphia workingmen to speak on the Fourth of July to one of the first citywide associations of labor unions in the United States. She asked if the Revolution had been fought "to crush down the sons and daughters of your country's industry under . . . neglect, poverty, vice, starvation and disease . . " and condemned the use of child labor.
July 4, 1930 - The National Unemployed Council was organized in Chicago to agitate for relief for the millions without work during the Great Depression.