Two years after President Biden became the first U.S. president to formally commemorate Indigenous Peoples’ Day, more than a dozen states recognize some version of the holiday in lieu of Columbus Day.

More than 100 cities have adopted the holiday, choosing to heed calls from Indigenous groups and other activists not to celebrate Christopher Columbus, the Italian navigator after whom the holiday is named. They say he brought genocide and colonization to communities that had been in the Americas for thousands of years. Many around the country, however, still celebrate Columbus Day or Italian Heritage Day as a point of pride.

Some members of Indigenous communities say recognizing the day, which this year is on Monday, Oct. 9, does not go far enough. It is not yet a federal holiday, though lawmakers in Congress have introduced legislation that proposes to make it one. Here is more background.

What is Indigenous Peoples’ Day?

Typically on the second Monday of October, Indigenous Peoples’ Day recognizes the Indigenous communities that have lived in the Americas for thousands of years. It became increasingly popular as a replacement for Columbus Day, which was meant to celebrate the explorer who sailed with a crew from Spain in three ships, the Nina, Pinta and Santa Maria, in 1492.

In a proclamation for last year’s holiday, President Biden said that Indigenous Peoples’ Day is intended to “honor the sovereignty, resilience and immense contributions that Native Americans have made to the world.”

But he added that “we have more to do to help lift Tribal communities from the shadow of our broken promises, to protect their right to vote and to help them access other opportunities that their ancestors were long denied.”

This month, lawmakers from the House and Senate reintroduced a bill that would establish Indigenous Peoples’ Day as a federal holiday on the second Monday of October, replacing Columbus Day. The bill, according to the lawmakers, has 56 co-sponsors in the House and several co-sponsors in the Senate. Tribes including the Cherokee Nation and the Navajo Nation have expressed their support.

Before the president’s initial proclamation in 2021, many U.S. cities and states were observing Indigenous Peoples’ Day. Colleges and companies have also increasingly recognized it. South Dakota is believed to be the first state to have officially recognized the day (as Native American Day) in 1990. Native Americans make up about 8.5 percent of the state’s population, according to census figures from 2022. Alaska, Oregon and Vermont are among the states that also officially established the day as a holiday; many other states recognize it through proclamations. Cities like Berkeley, Calif., Seattle and Minneapolis also were early adopters.

Similar commemorative days exist under other names around the world. Canada has been recognizing a National Indigenous Peoples Day on June 21 since 1996, and the country honored the first National Day for Truth and Reconciliation on Sept. 30, 2021. The government there has apologized at various instances for the suppression and forced assimilation of Indigenous communities.

In recent years, statues of Columbus have been taken down in cities around the world, including in Mexico City.

Are there closures for the day?

The United States Postal Service and post offices will be closed in observation of Columbus Day, as will most banks. Most government offices and libraries will be closed. Stores like Walmart and Target and most grocery stores are open.

In some cities, trash and recycling collection will be suspended.

How do Indigenous groups feel about the day?

Activists in cities such as Denver and Seattle have protested Columbus Day for years and in many cases have fought to gain recognition for Indigenous Peoples’ Day. Unofficial celebrations of Indigenous cultures have also taken place, including on New York’s Randall’s Island.

The Navajo Nation, the country’s largest tribe with about 400,000 people, has long voiced its support for renaming the day.

“Transforming Columbus Day to Indigenous Peoples’ Day will encourage young Navajos to have pride in the place and people they come from and the beauty they hold within,” Jonathan Nez, the president of Navajo Nation, said in a statement in 2021 before Mr. Biden’s first proclamation.

However, some say mere observance of the day does not do enough, and point out that no American president has explicitly apologized for the country’s treatment of Indigenous peoples. Others call it an important first step.

“I think it really recognizes that Indigenous people are still here,” said Alannah Hurley, executive director of United Tribes of Bristol Bay, a consortium of Indigenous communities in Southwest Alaska, and a Yup’ik fisherwoman. “We just have been struggling for so long for the vast majority of mainstream America and culture to recognize that — that we are not just in history books.”

She added, “We’re still fighting for our lands and our waters and our way of life. That visibility is huge because we have struggled for so long with being made invisible by mainstream society.”

What are some of the major issues Indigenous peoples face?

Supporters of the day say it may help bring attention to some of the ways Indigenous peoples are discriminated against and are disproportionately affected by climate change, gender violence and health issues, as well as to the Indigenous lands affected by mining, drilling and both public and private projects.

Audra Simpson, professor of anthropology at Columbia University, points to “the pipelines and fracking projects running through our territories” and “the ongoing and disproportionate violence directed at Indigenous people, especially women, girls and trans.”

The interior secretary Deb Haaland, the first Native American to hold that post, had made that violence a priority with the establishment of a Missing and Murdered Unit within the Bureau of Indian Affairs, Ms. Simpson noted.

In June, the Justice Department announced findings from a multiyear investigation into the Minneapolis Police Department that said officers there had routinely discriminated against Black and Native American people, used deadly force without justification and violated the First Amendment rights of protesters and journalists.

Later that month, the Supreme Court ruled against the Navajo Nation in a water rights case, rejecting the tribe’s suit against the federal government in a dispute over access to the drought-depleted Colorado River system.

In another case, Ms. Hurley’s organization of 15 tribes fought over the last few years to stop the construction of the Pebble Mine, a copper and gold mine in a major salmon fishery that Indigenous communities argued will pollute the Bristol Bay in Southwest Alaska.

This year, the Environmental Protection Agency blocked the project, citing concerns over its impacts on the ecosystem that houses the world’s largest sockeye salmon run. Alaska has appealed the E.P.A’s decision to the Supreme Court.

“There is much greater attention — media attention, public attention — paid to Indigenous peoples’ struggles and value than was the case 50 years ago,” said Jonathan Mazower, communications director for Survival International, an organization that works with and champions the rights of Indigenous communities around the world.

What about Italian Heritage Day?

Some Italian communities have called for a day separate from Columbus Day to celebrate their heritage, as Columbus Day originated partly as a response to anti-Italian sentiment. It was designated a national holiday in 1934, and in 1971 the government declared it a federal holiday to be celebrated the second Monday of each October.

New York City schools have tried to compromise by labeling the day as both Indigenous Peoples’ Day and Italian Heritage Day, nixing the Columbus Day title. There are still large Columbus Day and Italian heritage celebrations around the country, including the long-running parades in New York and the San Francisco area.

Mr. Biden issued a separate proclamation last year for Columbus Day, saying that “the hard work, dedication to community and leadership of Italian Americans in every industry make our country stronger, more prosperous and more vibrant.”

Ava Sasani and Catie Edmondson contributed reporting.