Deism is the belief in a God based on natural religion only. It is concerned with those truths which humans can discover through a process of reasoning, independent of any divine revelation through scripture or personal relevation.
Some Deists hold the belief that the universe was created by a God who then made no further intervention in its affairs, often expressed by the metaphor of the "Divine Watchmaker" who created a mechanism so perfect as to be self-regulating. Others share the theistic outlook that God is still active today. Deists do not believe in miracles or revelations.
Thomas Jefferson is perhaps the most well known and outspoken of the American founding deists. Thomas Paine was also a deist, The Age of Reason being one publication which particularly expressed this view. Benjamin Franklin seems also to have shared components of this view.