It has been nearly one year since former NDP leader Jack Layton died of cancer and Canadians are now preparing to gather to mark the anniversary and to celebrate his life and legacy.

Final preparations are underway for an event on the anniversary on Wednesday at Toronto's Nathan Phillips Square called "a celebration of love, hope, and optimism." The theme is a nod to the words in Layton's final letter to Canadians that he wrote before he died last Aug. 22.

That letter will be read out and musicians including Ron Sexsmith, Raffi, Jason Collett and Lorraine Segato will perform at the event, scheduled to begin at 6 p.m. Organizers also promise other surprise guests. Layton's widow, NDP MP Olivia Chow, his children Mike and Sarah, and other friends and family will be there.

"It's going to be quite a celebration, not just about Jack but all those people who believe we can make a difference based on the values of hope and optimism," Chow said in an interview.

A website launched this summer by the Broadbent Institute encourages Canadians to express how they are incorporating Layton's message into their lives and to share their memories of the political leader.

Layton's son Mike, a Toronto city councillor like his father, said the website has been a success and he's enjoyed reading the messages on dearjack.ca. He's looking forward to Wednesday's gathering, which comes just a few days before his wedding.

"It will be nice to have an opportunity to remember my dad and to reaffirm our commitment to the love, hope and optimism that he wanted us to continue to bring to the world," he said. "And to do that with friends, with music, with the arts, these are all things that my dad really loved and he would have appreciated."

Olivia Chow leads Jack Layton's children and their partners as they walk over a chalk drawing of a mustache at Nathan Phillips Square during Layton's funeral procession on August 27, 2011. (Ryan Remiorz/Canadian Press)

Nathan Phillips Square is the public space outside of Toronto City Hall and in the wake of Layton's death it was covered with messages written in chalk, flowers and other tributes. Inside city hall, his body lay in repose and long lines of mourners paid their respects, just as they had when he lay in state on Parliament Hill. Layton was a city councillor in the 1980s before he switched to federal politics.

While the Toronto gathering is the marquee event to mark the first anniversary of Layton's death, there are other events planned across the country in the following cities:

Thunder Bay

Calgary

Ottawa

Regina

Sudbury

Edmonton

Saskatoon

Montreal

Brampton

Winnipeg

Quebec City

Sherbrooke

Vancouver

Organizers in Calgary, for example, are planning to serve Orange Crush and stream the Toronto event online. The NDP's sweep of Quebec in the last federal election which pushed Layton into the role of Official Opposition leader was known as the Orange Crush because orange is the NDP's colour.

In Ottawa, people are planning on gathering at the Centennial Flame on Parliament Hill at 11 a.m. for a vigil and a picnic in a park is scheduled for the evening.

Chow said she's been receiving messages over the last few days from people telling her how they plan to mark the anniversary.

Historic cemetery Layton's final resting place

"It's a way to connect Canadians, no matter where they are," she said of the events.

Chow also attended an event on Saturday billed as "riding in the riding," which began at 2 p.m. at NDP MPP Jagmeet Singh's Brampton office.

Chow said the family will take some private time on Wednesday to mark the anniversary. Layton's ashes will be interred in the morning at the Toronto Necropolis cemetery, one of the city's most historic burial sites and one that had special meaning to Layton.

"He wanted to be buried there," said Chow. The City of Toronto operates historic walking tours through the cemetery and Layton used to lead them, dressed up as William Lyon McKenzie, who is also buried there.

But Layton nearly didn't get his wish to be buried at the Necropolis because when Chow called to get a plot she was told there were none available. In what was perhaps a twist of fate, a tree naturally fell down at the cemetery a few days later.

Chow, unaware of what happened with the tree, had decided not to take no for an answer and called the Necropolis back to see whether there was any way they could make room for Layton. She was told some space had been created because of the fallen tree and that, yes, she could have a plot after all.

"It's at a very good location," she said. His ashes are only being interred there now because of the special addition to his headstone, that Chow made with her bare hands over the last year.

Chow, who joked that she has no intention of ditching her day job to become a full-time artist, sculpted a bust of Layton, had it bronzed and recently affixed to the headstone.

The family will spend some time at the cemetery Wednesday morning, have lunch together, and later attend the Nathan Phillips Square celebration.

Their loss and their grief was a public affair last summer, and Chow said she has no problem with continuing to share it with Canadians.

"Connecting with other people is what he loved to do so of course myself and the family want to be with other people," she said.