Thanks to the online publication of the history of Mills County, Iowa, one of the first 'notable' Kisby's I came across was the pioneering Henry Kisby (1818-1908). He apparently emigrated from England in 1847, subsequently building up enough resources to buy himself a 50-acre farm in Glenwood Township. Henry's history is well documented in the 1881 "Mills County History", he was born 12 March 1818 in Lincolnshire, England and his first wife was also English, Ellen Needham, born c.1825.
What is puzzling is that I can find no trace whatsoever of a Henry Kisby in Lincolnshire that fits the bill. A Henry Kisby from Upwell, Cambridgeshire also emigrates to America in 1852, but he is a full 10 years younger. There are Henry's living in Huntingdonshire, but they can all be accounted for. Ellen, on the other hand, may have came from anywhere in England.
Maybe Henry changed his name when he arrived on America's shores. Whatever the explanation, it's a mystery I'd be delighted to solve!