If you look at the censuses page by page, you can see where people boarded and sometimes on the left side of the page it will say "Boarding House". This will be time consuming, but it is the only way that I know of as to how to find boarding houses or people boarding with others prior to when city directories were issued. If I remember correctly, Mr. Hernandez was here in 1861 and the downtown Jacksonville Library has city directories beginning with 1870. If Mr. Hernandez was here in 1861, to find a boarding house, you may want to check the 1860 census. The 1860 census is not all that big and can be checked fairly quickly. I doubt that Mr. Hernandez will be on there, but someone may want to check just to be sure.