looking for family

Hello, My father, James Vincent Sullivan, was born Sept. 20 1950 and adopted by Helene, ?-2003 and Roy, 1910-1982, Sullivan. They were residents of Galveston TX. My father was married a few times. First wife was Suzanne Phielschiefter #2 was Thi Vo and the third was my mother Cindy Manis. I don't know where he was born. I honestly know more about his adopted family than I do of him. He died in 2010 in NM. Please, if anyone has any information they can share I would greatly appreciate it. I'm curious about my heritage