The <a href="https://en.wikipedia.org/wiki/John_Bull_(locomotive)" id="mwAVk" rel="mw:WikiLink" title="John Bull (locomotive)">John Bull</a> becomes the oldest operable <a href="https://en.wikipedia.org/wiki/Steam_locomotive" id="mwAVo" rel="mw:WikiLink" title="Steam locomotive">steam locomotive</a> in the world when the <a href="https://en.wikipedia.org/wiki/Smithsonian_Institution" id="mwAVs" rel="mw:WikiLink" title="Smithsonian Institution">Smithsonian Institution</a> operates it under its own power outside Washington, D.C.