Is there an API available for downloading data from The National Map?
USGS has developed a ScienceBase Product Index API that will support calling our catalog of over two million staged data files. This API allows other applications to have download capability inside their own framework, and to filter on themes of interest, such as Orthoimagery, Elevation, Hydrography, or Land Cover, or by area of interest. In addition to ScienceBase catalog access, USGS also offers a TNM Download Client for advanced search capabilities for downloading staged products from The National Map.
Learn more: ScienceBase