Fireworks for personal use in the USA is restricted. For example, buying fireworks in Tennessee is legal. But, taking them into New Jersey is illegal. New Jersey has anti fireworks laws. Each US State has different regulations. As for US borders with Mexico or Canada, it's safe to say that it's illegal to take fireworks into the USA for personal use.
The U.S. Canadian border
"The purpose of US border patrol is to insure that persons crossing the border into the US are person that should be allowed into the country. The border patrol checks to make sure that persons entering the country are citizens, have a passport, or have a VISA."
Florida
None, unless canned or in the original package.
It is estimated that 130,000 tons of fireworks is imported into the US every year.
they share the largest border
2.5cm
only someone with a valid passport can enter the us ===================================== An "enhanced" driver's licence can be used for land crossings from Canada.
US Interstate 90 passes through South Dakota from the eastern to western border. US Interstate 29 passes through South Dakota from the northern to southern border.
They start in Canada, run through the US and terminate just north of the US/Mexico border.
There is not CLOSE border crossing between Texas and Canada, but you probably go through Detroit.
If you are that close to the border, you should have your papers in order. They should have allowed you a U-turn at the border, if possible. There is no fudging on the rules, regardless of your explanations: all you can do is to politely follow their requests and do as directed. That said, if you fit a profile, border patrol personnel will follow procedures that may seem excessive to you, but it is allowed.