I commonly see the assumption that Portugal did not have the manpower to colonise North America, when in reality before 1760, Portugal actually sent more migrants overseas than either Britain or Spain and far more than France.
By 1600 Portugal had already colonised the Azores and Madeira and both had a combined population of 150,000.
Portugal sent the bulk of its overseas colonists to Equatorial regions where the mortality rate was incredibly high. More settlers arrived in Luanda in a single year than the entire period of Dutch rule in the Cape. The other colonial powers did this as well, with more British and French settling in the West Indies than in North America, and many more settling in the disease prone south than in New England due to the attraction of cash crops. The far north of North America, north of the Chesapeake had an incredibly high rate of natural population increase. The net migration of French to New France was a mere 5,000 Frenchmen, but by 1840 their descendants numbered 400,000.
Far more British emigrated to the West Indies than mainland North America, between 1600 and 1780 two-thirds of all British emigration was to the West Indies. New England received a mere 30,000, a mere 4% of all of the British emigration overseas, but by 1780 the population of New England numbered 700,000. The Southern Colonies received seven times as many immigrants and the white population there only numbered 800,000 by 1780. In the West Indies the mortality rate was even higher with fewer than 100,000 whites living in the region.
Emigration from Europe Overseas
Portugal 330,000 (17% of 1580 population)
Spain 139,000 (1.85% of 1580 population)
Emigration from Europe to Colonies
1580-1640
Portugal 360,000 (18% of 1600 population)
Spain 188,000 (2.4% of 1600 population)
Britain & Ireland 126,000 (2.6% of 1600 population)
France 4,000 (0.02% of 1600 population)
Netherlands 2,000 (0.1% of 1600 population)
1640-1700
Britain & Ireland 248,000 (4.1% of 1700 population)
Spain 158,000 (3.1% of 1700 population)
Portugal 150,000 (7.1% of 1700 population)
France 23,000 (0.1% of 1700 population)
Netherlands 13,000 (0.68% of 1700 population)
1700-1760
Portugal 600,000 (26% of 1760 population)
Britain & Ireland 372,000 (5.6% of 1760 population)
Spain 193,000 (2.1% of 1760 population)
Germany 97,000 (0.5% of 1760 population)
France 27,000 (0.1% of 1760 population)
Netherlands 5,000 (0.19% of 1760 population)
1760-1820
Britain & Ireland 615,000 (3% of 1820 population)
Portugal 105,000 (3.5% of 1820 population)
Spain 70,000 (0.6% of 1820 population)
Germany 51,000 (0.19% of 1820 population)
France 20,000 (0.07% of 1820 population)
Netherlands 5,000 (0.2% of 1820 population)