Published in 1896, The Suppression of the African Slave-Trade to the United States of America, 1638-1870 is a remarkable and comprehensive study - it's online here. Its author, William Edward Burghardt Du Bois (1868-1963), was the first Black American to gain a PhD from Harvard - Carter G. Woodson was the second.
If you text-search it for "Ireland" you get various returns. Slave owners weren't the only ones to benefit from exploiting people. The colonial governments got a tax take from it too. Here's some pretty astonishing tax legislation from the General Assembly of South Carolina on 14 June 1751. It's quite the introduction –
"Whereas, the best way to prevent the mischiefs that may be attended by the great importation of negroes into this Province, will be to establish a method by which such importation should be made a necessary means of introducing a proportionable number of white inhabitants into the same...
Here's the section about 'negro' slaves –
"... That from and immediately after the passing of this Act, there shall be imposed on and paid by all and every the inhabitants of this Province, and other person and persons whosoever, first purchasing any negro or other slave, hereafter to be imported, a certain tax or sum of:
• ten pounds current money for every such negro and other slave of the height of four feet two inches and upwards;
• and for every one under that height, and above three feet two inches, the sum of five pounds like money;
• and for all under three feet two inches, (sucking children excepted) two pounds and ten shillings like money..."
And here's the section about 'poor foreign protestant' indentured servants –
"... the same is hereby applied for payment of the sum of:
• six pounds proclamation money to every poor foreign protestant whatever from Europe, or other poor protestant (his Majesty's subject) who shall produce a certificate under the seal of any corporation, or a certificate under the hands of the minister and church-wardens of any parish, or the minister and elders of any church, meeting or congregation in Great Britain or Ireland, of the good character of such poor protestant, above the age of twelve and under the age of fifty years;
• and for payment of the sum of three pounds like money, to every such poor protestant under the age of twelve and above the age of two years; who shall come into this Province within the first three years of the said term of five years, and settle on any part of the southern frontier lying between Pon Pon and Savannah rivers, or in the central parts of this Province," etc. For the last two years the bounty is £4 and £2."
Black people categorised and valued by height; Europeans categorised and valued by age. And the government getting its tax cut. What a shocking era. This is way beyond my area of knowledge, so I'm just posting it here for others to follow up on.








