Here i'll help you out with a timeline.

1444 First public sale of African slaves in Lagos Portugal
1482 The Portugese build the first permannt Slave trading post in what is now Ghana, it handled 30,000 slaves a year.
1510 The first slaves arrive in the Spanish colonies. So Hispanics owned Afircan slaves before we did. Hmm.
1518 The first shipment of slaves arrives in the Americas. 74 years after the first Africans were taken. Oh no, there goes the neighborhood.
1562 John Hawkins becomes the first English man to trade in slaves. So 118 years after African slaves were taken, We get our first dedicated and known slave trader.

I think your anger needs to be aimed elsewhere. Lets get some Portugese hatred going in here.