By extension, real photographs take the illustrations found on postcards one step further. You will find photographs of places, people, clothing fashions, and other subjects for auction. A relatively new hobby for me is collecting stereographic photograph cards. I bought a stereographic viewer from the 1890s in an online auction and am now collecting the stereographic cards from various areas and time periods. These add to my understanding and enjoyment of my ancestors' lives and are a source of endless entertainment.
Military memorabilia is highly collectible too.
Military books, swords, medals of all types and periods, uniforms, insignia, pins, patches and stripes, equipment, weapons, photographs, flags, figurines, documents, and hundreds of other items can be found for auction. For example, I saw a Confederate Cross of Honor for auction on the Web. Money and Coins. Family Group Sheets. People are selling their family group sheets in online auctions these days.