NYC in 1609: Amazing project called Welikia–recreating what Manhattan looked like as a habitat in 1609 and related National Geographic article and interactive map.
Great article on using primary sources with all grade levels
List of questions about the 1755 Plan of the City of New York
What is a map?
What dates are on the map?
What places does it show?
What on the map looks unfamiliar?
What is the scale of the map?
Is the name of the mapmaker on the map?
Is there a title on the map?
Describe the legend of the map. What was important to the colonists?
For what reason was this map created? What evidence do we have for that?
Who do you think was the audience for this map?
How does it compare with current maps of this place?
What does this map tell you about the people who lived there?