The only way to escape the tyranny of each person having to provide for every essential need is by expanding social cooperation to such a degree that specialization becomes possible. At that point, people can meaningfully speak of the freedom to choose a specialization they like or at which they are competent. At that point, people can decide how to spend the surplus time made available through specialization. The formation of broader social groups and governments then, is undertaken as a means to achieve the most basic freedom rather than a departure from that basic freedom.
The benefits of expanded social cooperation lead to increasingly complex cooperative arrangements. Governments come into being to manage these increasingly complex cooperative arrangements, and to protect or enforce compliance with group norms through the exercise of state sanctioned violence. What passes for a statement of purpose in the United States Constitution is really no more than an expression of guiding principles for how the founders envisioned the American government carrying out its management, protection and enforcement functions.
Specifically, the United States Constitution provides its guiding principles in the following statement: "We the people of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."