You migh consider following parts of Adventure Cycling's Nothern Tier route, which extends from Anacortes, WA to Bar Harbor, ME. One advantage to using their maps is that services like campground, motels, grocery stores, bike shops and libraries are shown. I did the entire thing many years ago. Good crosssection of secenery. Highopights include the North Cascades Highway, Going to the Sun Road in Glacier National Park, the headwaters of the Mississippi at Lake Istasca, Niagara Falls (thge Ontario side) and the Erie Canal tow path. If you keep heading east you will cross the Adirondak Mountains and ride through quaint New Hampshire and Vermont.

Manhattan is tough to ride into. Coming from the west, the only way in by bike is the G. Washington Bridge. Google New York state bike routes. Alternatively, there are various ferries into the city from NJ. Chek out NY Waterways for starters.