Black history question. Any help, please?

walter tull , professional british footballer , and the first black , british army officer , died ww1 , mary seacole nurse crimea war , travelled from Jamaica to england to help the war effort , the british turned her down still went any way , popular account by soldiers was she was much nicer that florence nightingale , theres a figure of a blackman on nelsons column london represents the black sailors who fought at trafalgar , septimus severus black roman emperor invaded britain , for afro americans see link below ,