How did an impoverished English empire spread through North America, break into their own independent nation which would be become a sole superpower, while the rich and heavily established Spanish crown lacked the same long term success. Why?
u/drylaw touches on reasons for why Spanish colonies differed largely from English colonies in the New World here and here
However you might find more specific answers if you reconsider/better define what you mean by “successful” colonial empires.