Poughkeepsie was a giant in its own right in the past. In 1777, it was the capital of New York. Between the midpoints of the nineteenth and the twentieth centuries, it was a major industrial center and after that, a home to IBM. Unfortunately, the loss of IBM meant a loss for the city's economic structure, but this is temporary and there is still plenty to see. The Bardavon 1869 Opera House is one of the oldest theaters in the United States. Not only has it been renovated, it is in active use and you may want to see an actual production in the House, rather than just walk in. The Clinton House and the Glebe House served as the seat of New York government in 1777 and there, today, you can view exhibits depicting local history.
Then there is Locust Grove. This is a villa once owned by Samuel Morse, inventor of the telegraph, and the villa's grounds overlook the Hudson River and the Young Memorial Wildlife Sanctuary, all worth a stroll-through (or a stroll by, in the case of the river).
Poughkeepsie is mid-way between New York City and Albany on I-87. For more information on Poughkeepsie, look at the sidebar on the left-hand side of the site.