Many different types of governments have operated with this goal in mind, with varying degrees of success. Often, the most stable regimes are also the most repressive ones. Until the modern age, when our perspective if not the facts themselves have shifted and democracy was seen as an enforceable worldwide ideal, stability through dictatorship and the true subjection of a government or monarch's subjects was not only considered ethically appropriate, but even as ideal when compared to the instability created by increased individual liberty. The United States of America was perhaps the first major world government to be conceived with an eye to preserving both liberty and stability, and though cynics might regard this intention and the degree to which it has been acted upon and fulfilled with a heavy dose of skepticism, there is no doubting that an effort to ensure both of these values would continue to exist in a flourishing society was at the heart of the Founding Father's intentions, both during the Revolution and in the framing of the Constitution. The first four Articles of the Unites States Constitution define and describe the three different branches of the government; the way they are to be appointed or elected, their various powers, and their respective checks and balances on each other. The inefficiency that this separation of powers creates was a conscious construct on the part of the Constitution's framers; from personal experience, they had seen what could happen when one of the branches -- most commonly the executive in the form of the king, but there were also instances of legislative abuse as in the Rump Parliament of the English Revolution and even the Senate of ancient Rome -- was able to act too quickly with too much authority. By forcing government to slow down, and to let each branch have some positive and negative say in the workings of the others, the framers ensured that personal...

Each state is free to maneuver according to its own needs and situation, up to a certain degree. This provides the liberty needed to make Massachusetts profitable for fisherman and Pennsylvania work for corn farmers, to give an over-simplified example. At the same time, the limits on each state's independence and the forced cooperation between and among them creates a stable environment both in terms of military protection and the supposed assurance that business can be conducted without the worry that one state's laws will favor one party over another.
The first ten Amendments to the Constitution, known collectively as the Bill of Rights, were aimed more at increasing personal liberty than maintaining and ensuring stability, but a liberalist would argue that the freedoms granted by these amendments do, in fact, ensure stability to a greater extent than limits on them. This argument is hard to buy; though Soviet stability during the Cold War, at least as was reflected economically, hardly compares to the United States', it is specious at best to link this to the Soviet's controlled press or lack of firearms. As George Orwell demonstrates in his fictional but completely possible vision of the totalitarian state in 1984, control of speech means control of thought, and that can't lead to anything but increased stability. For a more tangible example, we need only look at World War II -- as long as Hitler was winning wars, his oppressive regime was one of the most stable in the world. Still, though the Bill of Rights does nothing to increase stability, and may even undermine it, this is a necessary and worthy price to pay for liberty.