His pamphlet Considerations on the Propriety of Imposing Taxes in the British Colonies, which laid out the grievances associated with the taxation without representation argument, it has been described as "the ablest effort of this kind produced in America".

Dulany's skill as a lawyer was widely regarded, though as a result of his support for the Crown during the Revolution his reputation would not endure after the war.

Dulany was a member of the Maryland legislative assembly from 1751 to 1754, he was appointed to the Governor's Council (1757–76) in recognition of his support for the colony's proprietary government.

[6] Despite this open and articulate opposition to the Stamp Act, Dulany remained a loyalist, and in that vein engaged in a famous newspaper discussion with Charles Carroll of Carrollton.

Charles Carroll, then relatively unknown, adopted the more populist argument, claiming that the government of Maryland had long been the monopoly of four families, the Ogles, the Taskers, the Bladens and the Dulanys.

[9] Eventually Dulany resorted to highly personal ad hominem attacks on "First Citizen", and Carroll responded, in statesmanlike fashion, with considerable restraint, arguing that when Antilles engaged in "virulent invective and illiberal abuse, we may fairly presume, that arguments are either wanting, or that ignorance or incapacity know not how to apply them".

He believed that protest rather than force should furnish the solution to America's problems, and that legal process, logic, and the "prudent" exercise of "agreements" would eventually prevail upon the British to concede the colonists' demands.