Multiple Url pointing to categories

Here is my problem. I had a guy work on a wordpress site for me and now can’t contact him. I have 12 urls that need to point to different content. He built a single wordpress site and designed a different category (which is ok with me) for each of my urls. I am now ready to point my urls at the site. My question is, can I point a url such as marengocountyland.com at a category and have the url still read marengocountyland.com while on all pages in that category. Keep in mind that another category on the site will have bibbcountyland.com pointed at it and so on. The reason he built them as categories instead of using multisite is because I want to be able to make a post and let it post to multiple categories/urls(separate sites to the reader end) Am I up the creek and need to start over with multisite or can this be done. Thanks for any feedback.