travis dunn/lost sibling

I have been doing my family search for about 20 years.But all my life I have been told that my father Travis Dennis/Doyle Dunn had been married previous to marrying my mother.There was a child born in april, 1937 of this union.There was a divorce before the child was born because he married my mother in March, 1937.Supposedly Travis married the young woman from OK, named Doris because she was pregnant simply to give the child a name.I have not been able to locate a marriage license, divorce decree, or a birth certificate.My parents are both gone now so I am starting my search for my lost sibling.The story goes that they met when Travis was stationed at Ft. Riley, Kansas and she worked nearby.She was from Oklahoma, he from Arkansas and both living in Kansas, I have tried all three states for birth certificate and some counties, but there are a lot of counties in the three states to look for marr. license or divorce decree.I have been told that the child was a boy and he was named Travis Dunn, Jr.If this info fits you or anyone you know, please reply.Thanks, Jo Dunn Sheppard