Final answer:
The Barons forced King John to sign the Magna Carta due to their discontent with his reign, which financially burdened them and the country. The Magna Carta introduced the principles of due process and restricted the king's power, ensuring that no free man could be punished without a lawful judgment, influencing future legal systems, including the United States Constitution.
Step-by-step explanation:
The Barons wanted King John to sign an agreement for protections enshrined in the Magna Carta due to their grievances against his rule. Discontent with King John's methods of financing wars, such as raising court fees and inheritance taxes to exorbitant rates and selling government appointments, the barons led a rebellion. The Magna Carta symbolized a vital step in the development of constitutional governance by requiring due process and the King's adherence to the law, and establishing the principle that no free man could be penalized without the lawful judgment of his peers.
King John's loss of Normandy and subsequent actions to regain lost territories were financed by means that burdened the barons, in effect making their demands for the Magna Carta not just a request for personal protections but also for a broader principle of justice and the concept of a ruler who is not above the law. This document was paramount in setting the foundation for many subsequent legal principles, including those embraced by the United States Constitution, such as due process and trial by jury, and it was viewed as a cornerstone of liberty for all English subjects by the time of the American Revolution.
The Magna Carta was therefore not only a response to immediate financial and political crises but also a forward-looking document that laid the groundwork for the modern judicial system and the protection of individual liberties.