Read the Declaratory Act text, a bill passed by Parliament passed to assert the idea that Parliament still had ultimate authority to tax and make laws for its American colonies. Parliament had to repeal the hated Stamp Act because Americans had boycotted British goods and brought the entire British economy to a halt. British merchants were unable to pay their bills and had let tens of thousands of workers go.
The members of Parliament knew they had to repeal, but were worried that it would make Parliament look weak. They certainly didn't agree with the Americans who said they had no right to tax them or make laws for the colonies, the two main arguments of the colonists.
Many said they would only vote for the repeal if a strong statement of Parliament's sovereignty over the colonies was made along with it. The result was the Declaratory Act, which was signed by King George III on March 18, 1766.
In the colonies, there was rejoicing over the repeal of the Stamp Act, but some leaders worried that the statement of the Declaratory Act revealed Parliament's true intentions and that there would be more taxes and unjust laws to come.
You can read the text of the Declaratory Act below.
AN ACT FOR THE BETTER SECURING THE DEPENDENCY OF HIS MAJESTY'S DOMINIONS IN AMERICA UPON THE CROWN AND PARLIAMENT OF GREAT BRITAIN
Whereas several of the houses of representatives in His Majesty's colonies and plantations in America have of late, against law, claimed to themselves, or to the general assemblies of the same, the sole and exclusive right of imposing duties and taxes upon His Majesty's subjects in the said colonies and plantations; and have, in pursuance of such claim, passed certain votes, resolutions, and orders derogatory to the legislative authority of Parliament, and inconsistent with the dependency of the said colonies and plantations upon the crown of Great Britain: may it therefore please Your Most Excellent Majesty that it may be declared, and be it declared by the king's Most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, That the said colonies and plantations in America have been, are, and of right ought to be, subordinate unto, and dependent upon the imperial crown and Parliament of Great Britain; and that the king's Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, of Great Britain, in Parliament assembled, had, hath, and of right ought to have, full power and authority to make laws and statutes of sufficient force and validity to bind the colonies and people of America, subjects of the crown of Great Britain, in all cases whatsoever.
II. And be it further declared and enacted by the authority aforesaid, That all resolutions, votes, orders, and proceedings, in any of the said colonies or plantations, whereby the power and authority of the Parliament of Great Britain to make laws and statutes as aforesaid is denied, or drawn into question, are, and are hereby declared to be, utterly null and void to all intents and purposes whatsoever.