Aaron Stewart Black family Manhattan

Aaron Stewart Black is my 3rd great grandfather, born Ireland in 1815, he married Anne Neilson or Nelson in 1844 and died in 1905. He owned an umbrella company with his brother in law for a while, before having his own store on Broadway, I believe there were actually 2 store fronts, at one time he had a patent on a part of the umbrella as well. After many years I have been able to gather a great deal of information but am wondering where I can search for information about his umbrella business in NY records or places.
Being able to connect with anyone else would be magnificent as well. Thank you.
Susen Black-Bryant