The Sons of Liberty was an organization formed in the years before the American Revolution.
In 1765 the British government who were unhappy supporting the 10,000 troops that they had stationed in the American colonies, decided to levy a tax on the colonies. This was called the Stamp Act of 1765. In the act anything that was printed in the colonies, whether it was a legal document, playing cards or anything in between, was required by law to be printed on paper that was created in London and had an embossed revenue stamp on it. This caused a series of legislative actions in various colonies in opposition to the stamp act, starting in Virgina. The motto for this resistance became "No taxation without Representation." This caused groups to form in all of the colonies who violently opposed the Stamp Act and other taxes that had been levied.
In August of 1765, the Sons of Liberty formed in Boston, Massachusetts. Soon a committee was formed in New York to communicate with other colonies and to coordinate efforts in opposing the taxes. Some of the violence that was incited led to the tar and feathering of tax collectors. This was meant to injure and humiliate the tax collectors.
On December 16th, 1773 the Sons of Liberty in Boston held their most famous act of rebellion against the tax acts. The Boston Tea Party had the members of the Sons of Liberty climbing on board British merchant ships and dumping taxed tea into Boston harbor. This action led directly to the American Revolution.
The Sons of Liberty in Boston was largely made of Freemasons from the area. Although it was not a Masonic organization and did not have an exclusive masonic membership, many of the leaders of the organization were Freemasons. A masonic legend holds that the night of Boston Tea Party, St. Andrew's Lodge of Boston which owned the Green Dragon tavern meeting place of both the lodge and the Sons of Liberty, had their regular meeting that night. In the minutes of the meeting it allegedly stated that the meeting was canceled due to lack of quorum. Presumably that all the members were off dumping tea in Boston Harbor.
Throughout the world, non-masonic organizations like the Sons of Liberty have sprung during time of revolution in countries. This includes in Philippines, Ecuador and Mexico.