Notice the image of the president at the time, Ulysses S. Grant. Also, since the first commercially viable typewriter in the US wasn't manufactured until 1873 by the gunsmiths Remington Arms, it's clear that this arrangement must represent a time nearing the end of Grant's presidency. The desk chair is an incongruous note, since it appears to be traditional Early American rock maple of the type more commonly found in the eastern US, especially New England.