Individualism–Collectivism Scale
You can trace the individualistic mindset of Americans to its founding. That pursuit of various individual freedoms fueled the don’t tread on me spirit. Whether it was the freedom of religion, the lawless expansion into occupied indigenous lands, or the right to practice morally bereft chattel slavery. Americans have demanded the room to pursue what they solely want no matter the impact to their neighbor. It is no surprise then that "the United States scores highest on the individualism end of [the individualism-collectivism scale ... and consequently] is the only industrialized country in the world that does not provide its citizens with universal health care."