Answer:
The American Revolution was the first revolutionary manifestation worldwide in which the liberal ideas of thinkers such as Locke or Rousseau were wielded as the main ideological components. Thus, the conception of the natural rights to life, liberty and the pursuit of happiness became the cornerstone on which the entire revolutionary movement was built.
Especially, the right to freedom (from a civil as well as a political and economic sense) was the basis of the colonists' claims to King George, since they considered that he constantly violated their rights and curtailed their individual freedoms.
Thus, once America was constituted as an independent nation with these rights as the fundamental ideological base of society, the idea of freedom began to transcend from the simple expression of will towards a stronger claim for equality among all inhabitants, based on the natural right to freedom that originated in human nature itself. For this reason, these liberal ideas were the ones that gave rise to the movements originated in the north of the nation, which sought the abolition of slavery based on the undeniable human condition of African Americans and their rights as human beings.