Keywords: stereoscope, stereoscopes, stereopticon, stereoviewer, stereoptic, stereo, view, stereoview, stereograph, stereographic, viewer, 3d, stereoscopic, graphoscope, stereographoscope, Brewster, Becker, Oliver W. Holmes, Joseph L. Bates, Keystone, Underwood, American Lens Company, Cadwell, Alexander Beckers, H. T. Anthony, Cosmorama, Page, H. C. White, Whiting View Company, James Lee, Willard, Quirolo, Ardito, J. A. & Company, Pattberg, R. Y. Young, American Stereoscopic Company, A. L. Hudson, National Stereoscopic Association, NSA, photography.