Heyer's mother, Susan Bro, told The Associated Press that she has been dreading the anniversary of her daughter's death for months. The Unite the Right event comes on the anniversary of last year's deadly Charlottesville demonstration.
Charlottesville Mayor Nikuyah Walker said her community has "absolutely not" healed one year after the violence.
"We want to claim our streets back, claim our public space back, claim our city back", Aheron said at the park.
But as the anniversary of the rally approached, Trump appeared to try to get ahead of Sunday's "Unite the Right 2" rally in Washington, D.C., and counterprotests by calling for unity.
Jason Kessler, the primary organizer of last summer's rally, sued the city of Charlottesville after it refused to issue him a permit for another event this weekend.
In Washington on Sunday, counterprotesters planned an afternoon program of music, speeches and poetry readings at Freedom Plaza, east of the White House. There will be a "Still Here, Still Strong" protest and march by a coalition of groups, including survivors of the Charlottesville auto attack; a "Rise Up and Fight Back Counter-Protest", hosted by Black Lives Matter DC; and a Trans and Queer #ResistDance Against White Supremacy.
Makia Green, who represents the Washington branch of Black Lives Matter, told Sunday's crowd that: "We know from experience that ignoring white nationalism doesn't work".
But Trump was already facing significant scrutiny for racially charged comments he'd made on social media recently about professional athletes - and newly surfaced allegations by Omarosa Manigault Newman that he used racial slurs on the set of the Apprentice. Some leading figures in the USA white nationalist movement have said they won't attend or have encouraged supporters to stay away.
Trump drew strong criticism in the days after the Charlottesville rally past year for equating white supremacists with counter-protesters and saying "both sides" were to blame. "I don't want other mothers to be in my spot", she said, her voice breaking with emotion.
The "Unite the Right" rally in a Charlottesville park was organized in 2017 by white supremacist and neo-Nazi groups to protest plans to remove a statue of Robert E. Lee, commander of the Confederate States Army during the U.S. Civil War.
Fighting broke out between attendees and counterprotesters that day.
Authorities eventually forced the crowd to disperse, but a auto later barrelled into the crowd of peaceful counterprotesters. A state police helicopter later crashed, killing two troopers.
Charlottesville authorities came under criticism last year for underestimating the potential for violence, and they're trying to mitigate conflict this year.
When the group arrived at Lafayette Park, another large crowd greeted them with boos, cries of "shame", and chants of "fascists go home" and "you are not welcome here".