Why weren't the freedoms guaranteed by the Constitution when it was written?

Madison was actually once the Bill of Rights' chief opponent. In his book, The Oath and the Office: A Guide to the Constitution for Future Presidents, Corey Brettschneider, a political science professor at Brown University, writes that when the founding father entered the race for Congress as a candidate for the state of Virginia in 1788, the issue of whether America needed a Bill of Rights was a dominating campaign issue. George Mason, a fellow Virginian, had refused to sign the Constitution without a Bill of Rights. But Madison argued it was unnecessary and perhaps even harmful.

The freedoms you are talking about are the Bill of Rights, which are the first 10 amendments in the United States Constitution, and guarantee citizens freedom and freedom from the government. The Bill of Rights was not in the original Constitution because the Federalists believed it was not necessary to have them. In 1791, the Bill of Rights was finally added to the United States Constitution, after the pushing of the Anti-Federalists to add it in. The Anti-Federalists, along with other citizens and groups, worked for the Bill of Rights to be added into the U. S. Constitution because they wanted to protect the freedoms of the citizens from the central government. They were scared the central government would abuse their power, like Great Britain did when they abused their laws and used "taxation without representation."