Donald Trump also appeared to mix up the Revolutionary War with the War of 1812. (FILE PHOTO)

Airports? In the 1700s? A historical flub landed in President Donald Trump's "Salute to America" speech on Thursday marking the US Independence Day holiday.

While praising the victories of the Continental Army over the British during the 1775-1783 Revolutionary War, Trump mentioned how that army "took over the airports."

There were, of course, no airports in the 1770s, not to mention airplanes, which were not invented until the 1900s.

Trump read his prepared speech from a teleprompter behind a bulletproof lectern streaked with rain. On Friday he told reporters that the teleprompter had gone "kaput."

"Actually, in the middle of that sentence it went out," Trump said of the teleprompter. "And that's not a good feeling."

"I guess the rain knocked out the teleprompter, but I knew the speech very well," he said, "so I was able to do it without a teleprompter.

"And it was actually hard to look at anyway, because there was rain all over it," he said.

Trump also appeared at one point during the speech to mix up the Revolutionary War with the War of 1812.

While talking about the Revolutionary War, Trump mentioned the "rockets' red glare," which had inspired lawyer Francis Scott Key to write the poem that became "The Star-Spangled Banner," now the US national anthem.

Key wrote it after watching a British fleet bombard Fort McHenry, in Maryland's Baltimore Harbor, in September 1814.

Trump mostly stuck to his prepared text during a nearly hour-long Fourth of July speech that repeatedly lauded the US armed forces and stayed out of partisan territory.