The Mississippi River is the longest river in the United States.

True
False

False

Explanation:

The Missouri River is the longest at 2,341 miles while the Mississippi is only at 2,320 miles, so it is longer by 21 miles.

"The Mississippi River is the second-longest river and chief river of the second-largest drainage system on the North American continent," - Wikipedia

"The Missouri River is the longest river in North America." - Wikipedia which leads to usgs.gov

maybe #3? try that i think its correct