The act removed the reference to the Protestant faith from the oath of allegiance, and guaranteed free practice of Catholicism and restored the Church's power to impose tithes.

Moreover, the act was seen by the colonists as a new model for administration, which would strip them of their self-elected assemblies, and appeared to void some of the colonies' land claims by granting most of the Ohio Country to the province of Quebec.

On 4 February 1775, Governor Guy Carleton wrote to General Thomas Gage that he believed the Canadiens to be generally happy with the Act, yet he also added: I must not however conceal from Your Excellency, that the Gentry, well disposed, and heartily desirous as they are, to serve the Crown, and to serve it with Zeal, when formed into regular Corps, do not relish commanding a bare Militia, they never were used to that Service under the French Government, (and perhaps for good Reasons) besides the sudden Dismission of the Canadian Regiment raised in 1764, without Gratuity or Recompence to Officers, who engaged in our Service almost immediately after the Cession of the Country, of taking any Notice of them since, tho' they all expected half pay, is still uppermost in their Thoughts, and not likely to encourage their engaging a second Time in the same Way; as to the Habitants or Peasantry, ever since the Civil Authority has been introduced into the Province, the Government of it has hung so loose, and retained so little Power, they have in a Manner emancipated themselves, and it will require Time, and discreet Management likewise, to recall them to their ancient Habits of Obedience and Discipline; considering all the new Ideas they have been acquiring for these ten years past, can it be thought they will be pleased at being suddenly, and without Preparation embodied into a Militia, and marched from their Families, Lands, and Habitations to remote Provinces, and all the Horrors of War, which they have already experienced; It would give appearance of Truth to the Language of our Sons of Sedition, at this very Moment busily employed instilling into their Minds, that the Act was passed merely to serve the present Purposes of Government, and in the full Intention of ruling over them with all the Despotism of their ancient Masters.

[10]On June 7, after having received word of the Battles of Lexington and Concord, as well as the capture of Fort Ticonderoga and Benedict Arnold's subsequent raid on Fort Saint-Jean, he wrote to Colonial Secretary Dartmouth: The little Force we have in the Province was immediately set in Motion, and ordered to assemble at or near St. John's; The Noblesse of this Neighbourhood were called upon to collect their Inhabitants, in order to defend themselves, the Savages of those Parts likewise had the same orders; but tho' the Gentlemen testified great Zeal, neither their Entreaties or their Example could prevail upon the People; a few of the Gentry, consisting principally of the Youth, residing in this Place, and its Neighbourhood, formed a small Corps of Volunteers under the Command of Mr. Samuel Mackay, and took Post at St. John's; the Indians shewed as much Backwardness as the Canadian Peasantry.

...[11]Less than a month later, on 28 June 1775, Chief Justice William Hey wrote to the Lord Chancellor from Quebec: What will be your Lordships astonishment when I tell you that an Act passed for the express purpose of gratifying the Canadians & which was supposed to comprehend all that they either wished or wanted is become the first object of their discontent & dislike.

[12]On 21 September 1775, Lieutenant-Governor Cramahé, who governed at Quebec while Carleton was in Montreal, wrote to Dartmouth on the failure to rally the people after word arrived of the impending invasion from the colonies to the south: My Lord !

I am sorry to transmit to Your Lordship the disagreeable account of a disagreeable Business, some time in the Beginning of this Month, upon news of the Rebel Army approaching, General Carleton set out for Montreal in great Haste; the 7th instant the Rebels landed in the Woods near St. John's, and beat back to their Boats by a Party of Savages incamped at that Place; in this Action the Savages behaved with great Spirit and Resolution, and had they remained firm to our Interests, probably the Province would have been safe for this Year, but finding the Canadians in General averse to the taking up Arms for the Defence of their Country, they withdrew, and made their Peace.

After their Defeat the Rebels retired to the Isle aux Noix, where they continued till lately, sending out some Parties, and many Emissaries, to debauch the Minds of the Canadians and Indians, in which they have proved too successful, and for which they were too well prepared by the Cabals and Intrigues of these two last years; We knew of their being reinforced, and very considerably, I suppose, as they appeared in Numbers near St. John's last Sunday Evening; where or when they landed, or the Particulars since, we have but very imperfect Accounts of, all Communications with the Forts of St. John's and Chambli, being, as far as I can find, entirely cut off.

The Justice must be done to the Gentry, Clergy, and most of the Bourgeoisie, that they have shewen the greatest Zeal and Fidelity to the King's Service, and exerted their best endeavours to reclaim their infatuated Countrymen; ...[13]The Quebec Act angered some Americans.

The Quebec Act's main significance in the Thirteen Colonies was that it angered the Patriots, and dismayed the Loyalists who supported the Crown, and helped to accelerate the confrontation that became the American Revolution.