Small town boyfriend's parents disapprove of big-city girlfriend?

I lived my entire life in one of the biggest cities in the US. I decided to go to college away from the big city about 2 hours away. The town I go to school in has a population of about 12,000 people, and to me that is tiny! Anyways, I've been dating my boyfriend for over a year, and he is from another small town even further away. Everyone in his town seems to know everyone, and whenever I go home with him, it is apparent that the town is very cliquey. His family is also quite racist. His relatives are all farmers, and there is nothing wrong with that, but my boyfriend is a first generation college student. He is paying for his college out of his pocket, and he works two jobs. His family and friends always make fun of him for being in school when he comes home, and I think it is very sad. The people from his hometown are really not like him at all. No one there really goes to college, and when they met me, they immediately gave me cruel nicknames. They called me "boots" when I wore UGG boots, and they act like i'm a prissy rich girl who doesn't appreciate them. I am not like that at all. I am going to graduate next spring, and I'm only 19 years old. I have a 3.8 GPA, and it will only take me 3 years to graduate in total, and I work. I am a very driven, outgoing, and open-minded person. I would not have moved out of the big city to go to school if I was close-minded. It just really hurts my feelings when his mom always tells him should go hang out with his ex-girlfriends in front of me. She is always telling him what they are up to and how they miss him, etc. None of his ex's are going to college or tech school or anything. It really just kills me to see that they are so closed to me. It really feels like it's because i'm from the city, and I'm sick of it. I am a very good girlfriend, their son is obviously happy with me, and I am a very driven and smart girl. How can I get them to realize i'm not an outsider. My boyfriend tells me he wants to spend the rest of his life with me, and he tells me how happy I make him, but I can't picture myself with a guy who's family hates me. He tells his parents how much he likes me, and he ignores them when they talk about his exs, but his parents don't get the hint. How can I get them to stop obsessing over his exs and realize i'm the girl their son wants?