**Southern Coast of Long Island From Montaukpoint to East Hampton INDIGO, 1877** This U.S. Coast Survey chart documents the southern shoreline of Long Island from Montauk Point to East Hampton, produced during the post-Civil War expansion of American maritime mapping. The survey captures the detailed bathymetry and coastal features of this historically significant whaling and fishing region at the height of Long Island's maritime economy. Printed in the distinctive indigo blue characteristic of period nautical charts, with exceptional clarity in the depth soundings and coastal topography.