US President Donald Trump has made a direct appeal to disaffected white voters four months before Election Day, accusing protesters who have pushed for racial justice of engaging in a “merciless campaign to wipe out our history.”

Speaking at the foot of Mount Rushmore on the eve of Independence Day, the President dug further into American divisions on Friday (local time), offering a discordant tone to an electorate battered by a pandemic and wounded by racial injustice following the high-profile killings of black people.

He zeroed in on the desecration by some protesters of monuments and statues across the country that honour those who have benefited from slavery, including some past presidents.

Mr Trump revealed he has a vision for his second term of establishing a “National Garden of American Heroes” that will pay tribute to some of the most prominent figures in US history, a collection of “the greatest Americans to ever live”.

It would include George Washington, Thomas Jefferson, Abraham Lincoln and Martin Luther King Jr, all already represented on or near the National Mall in Washington DC.

It would also feature Susan B. Anthony, Daniel Boone, Davy Crockett, Frederick Douglass, Amelia Earhart, Billy Graham, Douglas MacArthur, Christa McAuliffe, Jackie Robinson, Betsy Ross, Harriet Beecher Stowe, Harriet Tubman, Booker T. Washington and Orville and Wilbur Wright.

The group of 30-plus features Founding Fathers and presidents, civil rights pioneers and aviation innovators, explorers and generals.

US President Donald Trump rallies his supporters on the Fourth of July. Photo: Getty

Mr Trump lamented “cancel culture” and charged that some on the political left hope to “defame our heroes, erase our values, and indoctrinate our children.”

He said Americans should speak proudly of their heritage and shouldn’t have to apologise for its history.

“We will not be terrorised, we will not be demeaned, and we will not be intimidated by bad, evil people,” Mr Trump added.

“It will not happen.”

The speech and fireworks at Mount Rushmore came against the backdrop of a pandemic that has killed over 125,000 Americans.

The president flew across the nation to gather a big crowd of supporters, most of them without and all of them flouting public health guidelines that recommend not gathering in large groups.

A Black Lives Matter activist and a Trump supporter trade words in Pittsburgh, Pennsylvania on July 4th. Photo: Getty

Amid the campaign headwinds, the president has sharpened his focus on his most ardent base of supporters as concern grows inside his campaign that his poll numbers in the battleground states that will decide the 2020 election are slipping.

Mr Trump in recent weeks has increasingly lashed out at “left-wing mobs,” used a racist epithet to refer to the coronavirus and visited the nation’s southern border to spotlight progress on his 2016 campaign promise to build a US-Mexico border wall.

The event, while not a campaign rally, had the feel of one as the friendly crowd greeted Trump with chants of “Four more years!” and cheered enthusiastically as he and first lady Melania Trump took the stage.

“They think the American people are weak and soft and submissive,” Mr Trump said.

“But no, the American people are strong and proud, and they will not allow our country and all of its values, history and culture to be taken from them.”

US President Donald Trump and First Lady Melania Trump at Mount Rushmore on American Independence Day. Photo: Getty

-with agencies