I really shouldn't call it my first case. I wasn't a PI yet, but I had just given up police work in Missouri and moved back to Wichita. I was rooming with my best friend and working odd jobs until something solid came about.
I knew that my friend had been adopted and was wanting to find his birth parents. Fortunately, Kansas is one of only eight states that have full disclosure of adoptions once the the adopted child is of age. My friend sent off for the records of adoption, which is handled by the Kansas Dept. of Health and Environment. Once he had the paperwork he found out his birth mother's name.
The next step was to locate her. This is where I joined the search. Following my instructions, he stopped by the main branch of the public library. We looked in an old phone book from the year he was born and compared it to the recent issue of the phone book to locate people who possessed the same last name, and who were still around. The idea was to contact them, even if they weren't the birth mother, because it was reasonable to assume they might be related to her.
We found the name of a married couple that had lived at the same address and with the same phone number for the last three decades.
My friend was too nervous to call and he asked me to do it. I agreed and I contacted the people. I was grilled pretty hard at first, but soon found out that we had found my friend's maternal grandparents. We found out that his mother had been looking for him, and indeed, she had tried to reverse the adoption a few weeks after it was completed, but was unsuccessful. In short order, a very happy and tearful reuninon occurred. My friend found himself a part of large extended family and that he had an older sister and a younger half-sister.
Thus I completed my first "case" at finding someone. It is especially meaningful to me because I married his older sister.