The anniversary event, to take place in the country's northern Limpopo province on Saturday, comes days after a state-backed judicial investigation revealed how some of the party's top officials had benefited from corruption.
The ANC remains divided between those backing President Cyril Ramaphosa, who is also president of the party, and those loyal to former President Jacob Zuma, who has been embroiled in legal battles since he left office in 2018.
Zuma’s refusal to appear before the commission of inquiry saw him sentenced to 15 months in prison in July last year, which sparked riots that descended into widespread looting and destruction of property in the KwaZulu-Natal and Gauteng provinces. More than 340 people died in the rioting.
Ramaphosa acknowledged the problems when speaking to ANC supporters this week.
“We have lots of challenges, nearly on every front. We have COVID-19. We also had corruption scandals ... that we had to deal with. It involved people dipping their fingers into money that was supposed to be utilized for (personal protective gear)” said Ramaphosa, citing one of several corruption scandals.
He said the loss of jobs due to the COVID-19 had compounded South Africa’s already high unemployment rate of 34% and he highlighted the July unrest as one of the major events that set the country back.
“It’s a broad spectrum of challenges and problems. It needs leadership but also needs us to work together, and to ask ourselves whether we give in ... or are we going to defend the gains that we have made?” Ramaphosa said.
However, the ANC's support has declined in recent years and it received less than 50% of votes cast in local elections in October, its worst-ever showing at the polls.
The ANC will try to use the anniversary to win back some of the support they have lost over the years, political analyst Hlengiwe Ndlovu said.
The ANC's poor showing in the October elections was significant, she said. "That was a clear message from South Africans to say ‘We are tired. We see what you are doing and we are starting to look outside,’” said Ndlovu.
She said Ramaphosa and others will “try to push the message of unity within the party, but the factionalism within the party is very clear, as we saw with the Jacob Zuma support protests," she said.
Fewer people will attend the anniversary event Saturday as a result of COVID-19 regulations, which restrict gatherings to a maximum of 2,000 people.