Mortgage lenders mapped areas based on what they considered to be risky investment areas. The areas they deemed less secure risks were outlined on the maps in red. Because of this it was much harder for people to get loans to buy property in poorer areas, black neighborhoods, and areas with large immigrant populations. On this 1938 map, Red Hook is mostly in red except for the areas, industrial and commercial. The practice of 'red lining' is now illegal.
This map was made by the Hagstrom map company using data from the Home Owners' Loan Association