The api is designed for editing the openstreetmap data. It has a limit how big an are area you are allowed to download at once. The whole of Baltimore is certainly too much. Clicking on the [export button][1] at the top of the the openstreetmap main page list some alternatives if the export from the api fails, because the area is too big. E.g.: http://overpass-api.de/api/map?bbox=-76.7237,39.1971,-76.5273,39.3858 and http://metro.teczno.com/#dc-baltimore [1]: http://www.openstreetmap.org/export#map=12/39.2915/-76.6255

The api is designed for editing the openstreetmap data. It has a limit how big an are you are allowed to download at once. The whole of Baltimore is certainly too much. Clicking on the [export button][1] at the top of the the openstreetmap main page list some alternatives if the export from the api fails, because the area is too big. E.g.: http://overpass-api.de/api/map?bbox=-76.7237,39.1971,-76.5273,39.3858 and http://metro.teczno.com/#dc-baltimore [1]: http://www.openstreetmap.org/export#map=12/39.2915/-76.6255