Can we consider the American philosophy of the 17th century pure American?

This depends on what your definition of “pure American” is. In summary, the American philosophy of the 17th century was defined by English settlements composed of a variety of Christian denominations, primarily Puritan and Methodist. These growing settlements laid the groundwork for American democracy by staunchly defending religious freedom. While they often discouraged religious free thinking among their own people, each Protestant group shared the common belief that a monarch should not enforce a particular mode or object of worship upon his or her people. After all, that was why the Pilgrims, for example, were in America rather than Europe. However, much political and social change would need to take place before the values of religious freedom and individual liberty would be more holistically applied, especially as it concerned age, race, and gender.
One school of thought focuses on the core of American philosophy and sees purity in whether that core is maintained. In other words, this perspective would claim that American philosophy of the 17th century contained enough of a sense of individual liberty and freedom relative to its time that it could be considered pure. The opposing perspective maintains that the cultural and social ills of the time (i.e., slavery, no voting rights for women and non–land owners, etc.) relative to today’s values place the America of that time in a category outside of “pure American.” You may even consider these two perspectives as two points along a spectrum of historical interpretation as you consider to what extent 17th-century American philosophy is “pure American.”