text: First of all compliments for this fantastic site!!!
  I have noted a serious error in the Ellis Island map about the territorial division between New Jersey State and New York State.
  The EXACT and FINAL map is the FIGURE 10 in this document (https://web.archive.org/web/20141018003341/http://proceedings.esri.com/library/userconf/proc99/proceed/papers/pap138/p138.htm). In fact in 1998 the United States Supreme Court accepted the final map and New York was granted jurisdiction to 4.68 acres. This area includes almost all of the Main Immigration Building as well as portions of the Wall of Honor, baggage handling/dormitory building, power house and administration building (Figure 10). The New York portion of Ellis Island is landlocked, enclaved within New Jersey's territory. New Jersey has sovereign authority over the remaining 22.80 acres of the island that includes portions of the above buildings, the ferry house, and all of the 29 hospital and dormitory buildings located on the southern portion of the island.
  
  Another 100% exact map is this: http://www.schundler.net/Ellis%20Island%20Map%20Color.pdf
  
   I think that it is necessary TO REPLACE the wrong dotted boundaries in the your map with the exact dotted boundaries.
  Thanks for the possiblle corrections!!