US President Donald Trump has blamed a teleprompter going "kaput" for a glaring anachronism in his Independence Day speech.
He told crowds on 4 July the Continental Army "took over the airports" during the American Revolutionary War in the 1770s.
Observers quickly pointed out there was no air travel in 18th Century America.
Explaining away the slip-up on Friday, Mr Trump also said it was hard to read the teleprompter in the rain.
During his "Salute to America" speech at the Lincoln Memorial on Thursday, he was talking about the year 1775 when he said: "Our army manned the air, it rammed the ramparts, it took over the airports, it did everything it had to do."
Critics pointed out the rebels could not have seized airports more than a century before the first powered flight - credited to the Wright brothers in 1903 - took off.
In the same sentence, Mr Trump also appeared to date a battle at Fort McHenry to the American Revolution, when it unfolded decades later during the War of 1812.
Twitter users had some fun with the garble, using the hashtag #RevolutionaryWarAirports.
Outside the White House on Friday, Mr Trump said: "I guess the rain knocked out the teleprompter.
"I knew the speech very well so I was able to do it without a teleprompter but the teleprompter did go out and it was actually hard to look at anyway because there was rain all over it but despite the rain it was just a fantastic evening."
The president spoke to reporters as he departed with First Lady Melania Trump for the weekend to his golf club in Bedminster, New Jersey.
Before winning the White House, Mr Trump used to criticise ex-President Barack Obama for relying on an autocue.
The president's Independence Day celebration saw military tanks transported into the nation's capital and a flyover by the Navy Blue Angels aerobatics team.
His critics had pilloried the event as inappropriately partisan and a misuse of public funds.
But Mr Trump surprised some by steering clear of overt partisanship in his speech, instead celebrating patriotic themes and US history including civil rights.
Before a cheering crowd on the steps of the monument to Civil War era-president Abraham Lincoln, he said the story of America was "the greatest political journey in human history".
He was the first president in nearly seven decades to address a crowd at the National Mall on the Fourth of July.