How do you find out if a dead relative left you money?

My grandmother recently told me that when my granny was on her death bed, she told my grandmother that her brother was going to leave me money. my granny's brother said that because he lost his wife and children in a fire many years before he died he wanted to claim me as the heir to his money. he was a very wealthy man. he died before i was born on july 22 which also happened to be his birthday as well. my own parents didn't even know that he ever considered leaving me money. and no one could touch it except me and not until i turned 18. i will be 18 in a year and a half but i want to know. i am curious. how would i go about finding a dead mans will/or learning whether or not i was left this money?? please help!!