The U.S. Constitution is old. But 400 years old? 

That's what Rep. Sheila Jackson Lee, D-Texas, seemed to claim during a floor speech on Wednesday. 

While speaking in opposition to a Republican-backed proposal, she launched into a brief history lesson. She said she wanted to thank her GOP colleagues "for giving us an opportunity to have a deliberative constitutional discussion that reinforces the sanctity of this nation and how well it is that we have lasted some 400 years operating under a Constitution that clearly defines what is constitutional and what is not." 

The math was off by nearly 200 years. The Constitution was adopted in 1787. 

Four-hundred years ago was more around the time of Jamestown, the first permanent British settlement on this side of the pond. 

Jackson Lee was speaking Wednesday in opposition to a bill that would speed up congressional lawsuits against the president for failing to enforce federal laws. The GOP-led House approved it on a 233-181 vote. 

Jackson Lee argued it was "not constitutional."