Philadelphia Convention was the venue for the writing of the United States Constitution in 1787. The old Congress established the rules that the new government would follow in writing and ratifying a Constitution. The Constitution was written to replace the Articles of Confederation because the Articles were deemed inadequate in protecting the rights of individual states. Preamble: The Constitution contains a preamble that explains why it was created. The Constitution also contains seven articles that outline the structure and functions of the government, as well the rights for the people.