Today, more so than ever, patents play an important role in helping inventors and organizations protect their intellectual property. With a 140% increase in the number of patents granted over the last 25 years, a rich source of data is available that can be examined to better understand changing trends in patent grants. In this paper we discuss visualization techniques that allow us to examine the classification of more than 2.5 million patents in an attempt to improve understanding of how an assignee?s patent portfolio, and the patent space as a whole, is partitioned and evolves over time.