He was born July 1, 1730 at West Brewster, Massachusetts the son of Joshua and Mary Sears. He was a descendant of Richard Sears, who emigrated to the colonies from Colchester, England, in 1630. While he was a child the family moved to Norwalk, Connecticut.
At the age of sixteen he was apprenticed to the skipper of a coastal vessel. By 1752, he was in command of a sloop trading between New York and Canada. Sears established his reputation as a privateer during the French and Indian War, commanding a vessel from 1758 until 1761, when he lost his ship. He moved to New York City and had become successful enough to become a merchant investing in ships engaging in trade with the West Indies.
Sons of Liberty
On October 31, 1765 the day before the Stamp Act was to take effect he was among the merchants assembled in New York City resolved to enforce opposition to distribution of the stamps and to curtail the importation of British goods. Sears organized and was a leader of the Sons of Liberty in 1765. They used violence and threats of violence to prevent the use of stamps. He was nicknamed "King Sears" for his influential role in organizing and leading the New York mob. He was at the head of nearly every demonstration of mob violence in New York City. He partnered with James DeLancey in opposition to the stamps and supported him in his 1768 election to the New York assembly. Sears and many of his followers were engaged in trade and they demanded that trade continue without stamps.
In 1766, Sears, John Lamb and three others formed a committee of correspondence to communicate with other Sons of Liberty groups in other provinces. After the Stamp Act was repealed the Sons of Liberty erected a Liberty pole to celebrate. When the British cut down the pole for the first time, Sears was injured in a confrontation with the British. In 1768, he and numerous New York merchants sent a petition to Parliament outlining their grievances on the state of trade. In 1769, when the New York assembly passed an appropriation for funding of the Quartering Act, he posted an inflammatory broadside entitled "To the betrayed inhabitants of the city and colony of New York".
In January 1770, confrontation led by Sears with the British over the posting of broadsides and the liberty poles resulted in the Battle of Golden Hill. The fifth liberty pole was raised in 1770 on a plot of land owned by Sears. When the Tea Act was passed in 1773, he organized the city's captains into refusing to freight the East Indian tea. It was the first organized opposition to the tax. Broadsides, signed "The Mohawks", were posted warning against anyone trying to land tea. New York's opposition was partly responsible for Boston's decision to stop the landing of tea. Adams wrote, "we must venture, and unless we do, we shall be discarded by the sons of liberty in the other colonies". They were successful in preventing the landing of tea. In April 1774, they boarded the Nancy and destroyed its tea.
During the Townsend Acts, Britain passed a Tea Act in 1773 to ship tea directly to North America to help the East India Company, saving it from being taxed so it can come out of bankruptcy. Sears and his companions believed that the ruin of their commerce was inevitable if they did not succeed in preventing the sale of India Company tea in America; they were convinced that this could be effected only by a total prohibition of English tea since otherwise the Company would find ways of sending its teas to America in the name of private merchants. He was also worried Britain would soon try to make a monopoly of other goods in the colonies, threatening the welfare of the Sons of Neptune. Before the tea was to be sent to the colonies, Captain Sears and McDougall decided an opposition was needed and sought to unite all the Sons of Neptune and Liberty with the merchants and tea-smugglers. The Sons of Liberty and the Dutch smugglers had come together and sparked the "New Flame" described by William Smith. As the tea approached the harbors of New York, Philadelphia, and Boston in early November the campaign began. The tea stood in the boats that were in the harbor and no one dared to remove them for fear of the tea being destroyed. Towards the end of November, McDougall from Sons of Liberty made a publication to be sent out to all harbors. “If any of the tea by any persons associated with the India Tea Company had accepted a commission to sell, land, or store the tea would be paid “an unwelcomed visit, in which they shall be treated as they deserve: by ‘The Mohawks.’” Thus Sears and McDougall initiated the use of this distinctively American name to cover the identity of those who were ready to employ violence to block the operation of the Tea Act." Not long after, the Boston Tea Party took place and the tea ships in Philadelphia and New York turned back to England for fear of their cargo.
When in May 1774 news of the Boston Port Act arrived, Sears and McDougall wrote a letter of support to Boston, without consulting anyone else, in addition to a British boycott, they proposed a ban on exports to the West Indies and called for a Continental Congress. Reaction in New York to the Boston Port Act was cautious and equivocal, there was a split with the DeLanceys on whether to proceed with nonimportantion.
Committee of Sixty
On May 16, 1774 a meeting at the Fraunces Tavern was called of the various factions. The Committee of Fifty was elected with Isaac Low as its chairman. James DeLancey's faction was in the majority, with Sears and his Sons of Liberty in the minority.
In 1774, he was a leading member of New York City's Committee of Sixty. In a letter to the Boston Committee of Correspondence he proposed a meeting of delegates from the principal towns. This proposal was initially disavowed by the Committee of Sixty, but later was ratified in a proposal for the meeting of the First Continental Congress.
On April 15, 1775 he was arrested for his anti-British activities, but was rescued at the prison door by his supporters and paraded through the streets as a hero. When news of the Battle of Lexington arrived he and his followers seized the arsenal at the Custom House. He was the de facto commander of New York City until Washington's Army arrived in June, 1776.
On November 20, 1775, Sears led a group of 80 citizens in apprehending Parson Seabury, Judge Fowler, and Lord Underhill. At some point the mob forced Fowler to write (or else they forged his name) an apology and a promise not to interfere with the Second Continental Congress. While some of the mob escorted the three prisoners to Connecticut, Sears led the remaining 75 in a march to James Rivington's Royal Gazette, where they destroyed the printing press (which was melted and made into bullets (presumably for the war effort)) in November 1775. According to the Diary of the American Revolution, Volume I:
- They then faced and wheeled to the left, and marched out of town to the tune of Yankee Doodle. A vast concourse of people assembled at the Coffee House, on their leaving the ground, and gave them three very hearty cheers.
The group then disarmed many of the loyalists along their route before disbanding.
After war years
After the British left New York City in 1783, he returned to the city installing himself in a mansion on the Bowling Green and reviving the Sons of Liberty. By March, he was calling for the expulsion of any remaining Loyalists in the state by May 1. He and other members of the Sons of Liberty won enough seats in the New York State Assembly in December, 1784 to enact a set of harsh anti-Loyalist laws. He was exposed for buying up soldier's pay certificates at depressed prices and using them to speculate in forfeited Loyalist property. The public regarded this as the height of venality and cynicism. He was again elected to the assembly in 1786, but by then he was deeply in debt and he left the state to avoid arrest. Sears became supercargo on a merchant ship on a trading venture to China. He contracted a fever and died in Canton on October 28, 1786.
- Dictionary of American Biography
- Ketchum, pg. 152
- Isaac Sears - Britannica Online Encyclopedia
- Ketchum, pg. 243
- Christen, pg. 298
- Christen, pg 282
- Moore, Frank.  (2001). Diary of the American Revolution Vol. I.: 122-123 Edited by Jay Carper. Internet: Third Millennium Publishing. ISBN 1-929381-81-6
- Schecter, pg. 385
- Isaac Sears.Dictionary of American Biography Base Set. American Council of Learned Societies, 1928-1936.
- Ketchum, Richard, Divided Loyalties, How the American Revolution came to New York, 2002, ISBN 0-8050-6120-7
- Schecter, Barnet, The Battle of New York, 2002, ISBN 0-8027-1374-2
- Christen, Robert J. "King Sears, Politician and Patriot in a Decade of Revolution." New York: Arno Press, 1968, ISBN 0-405-14077-0