National Treasure Fact or Fiction

1. Templar Treasure:
Fact: The Knights Templar were based at Temple Mount in Jerusalem during the Crusades. The Temple Mount is the traditional location of the Temple of Solomon. Soon after, the Order became wealthy and influential.
Fiction: The timing of their rise is what leads to conspiracy theories of the Templars' finding a treasure. However, the Templars had support and favor in the Church at that time. They also established what could be considered an early banking system that aided pilgrims on their trip to the Holy Land. It is this that led to the Templars rapid rise in influence and rapid decline after the Holy Land was lost to the Muslims.

2. Templars and Freemasons:
Fact: By the 18th century, the Freemasons were using some Templar symbols. Also, some of the Founding Fathers (including George Washington) were Masons. The Templars were officially disbanded in the early 14th century while the Freemasons didn't rise to prominance until the late 16th century.
Fiction: There are stories that some Templars fled to Scotland, which was outside of the Catholic Church's influence. There is some evidence that early Masonry might have appeared in Scotland in the late 14th century. This circumstantial evidence along with the 18th century Freemasons' use of Templar symbols leads to conspiracy theories that the Masons descend from Templars.

3. Freemason Influence on American Founding
Fact: Several Founding Fathers (including George Washington) were Masons. The Great Seal contains imagery used by Masons.
Fiction: Though cited as tying the Great Seal to Masons, the imagery was popular during the 18th century culture not just with Masons. Furthermore, final approval for use of the imagery was done by non-Masons.

4. Code in Silence Dogood Letters
Fact: The Silence Dogood Letters were written by Benjamin Franklin - a Mason. The Silence Dogood Letters were written by a sixteen-year-old Benjamin Franklin in 1722 in Boston. Franklin joined a Mason lodge in Pennsylvania in 1731. Masonry wasn't established in Massachusetts until the 1730's as well. Thomas Jefferson was fascinated by ciphers so it's possible that Franklin would have dabbled in them as well.
Fiction: Choosing some now-famous letters written by a Mason as a key for a code sounds catchy, but unlikely. Then again, a centuries-old treasure isn't exactly steeped in realism either.

5. Charles Carroll was the last living Signer of the Declaration
Fact: Charles Carroll was indeed the last surviving signer of the Declaration of Independence when he died in 1832. He was wealthy and a Catholic.
Fiction: Though Carroll's significance as a signer of the Declaration, his wealth and his Catholicism all tie into conspiracy theories, Catholics were not allowed to join the Masons.

6. Huge Treasure Chamber under the Trinity Church
Fiction: Just think about this; Manhattan is an island with significant development and a subway system. Now even if such an underground chamber had been built in the first place, it would not have escaped both discovery and significant damage in the last two hundred years. Another rumored location at Oak Island seems more plausible at this point in time.