It has been almost 50 years since the U.S. government established that Asian-Americans, Native Hawaiians and Pacific Islanders and their accomplishments should be recognized annually across the nation.

What started as just one week in May has evolved over the decades into a monthlong tribute of events in cities big and small. The nature of celebrations also evolved. Asian-American and Pacific Islander or Asian-American, Native Hawaiian and Pacific Islander Heritage Month is not just about showcasing festive fare like food and fashion, but hard subjects like grief and social justice. The rise of anti-Asian hate during the pandemic only heightened that effort.

“I think the visibility and the level that the increased participation of organizations in Asian Pacific Heritage Month activities is also an indication of the increasing voice of Asian Americans and Pacific Islanders in civic life more generally,” said Karen Umemoto, director of the UCLA Asian American Studies Center. “And also an indication of the spaces that we’ve come to collectively enter to be able to create those.”

Indeed, Asian-American and Pacific Islander Heritage Month celebrations are not relegated just to ethnic enclaves or culturally specific venues. Across the U.S. this year, events are planned at public libraries, parks and museums either highlighting a specific Asian culture or a myriad of them.

Many credit the observance’s origin to Jeanie Jew, a co-founder of the congressional Asian-Pacific staff caucus. In 1977, the Chinese American shared a moving story with New York Republican Rep. Frank Horton about how her grandfather had helped build the transcontinental railroad in the 1800s and then was killed amid anti-Asian unrest.

Ms. Jew believed Asians should appreciate their heritage and “Americans must know about the contributions and histories of the Asian-Pacific American experience,” Rep. Horton said in 1992, according to congressional archives. At that time, Black History Month and Hispanic Heritage Month already had been instituted. Yet, Asian-Americans were described as the fastest growing racial group.

Rep. Horton and California Democratic Rep. Norm Mineta proposed President Carter issue a proclamation that the first week of May be “Asian/Pacific American Heritage Week.” Hawaii Sens. Daniel Inouye and Spark Matsunaga, both Democrats, brought up a similar bill in the Senate.

May was chosen because of two significant events. The first Japanese immigrants to the U.S. arrived on May 7, 1843. Then on May 19, 1869, the final spike for the transcontinental railroad track, in which Chinese laborers played a crucial role, was embedded.

Ms. Umemoto recalls hearing talk of Asian Pacific Heritage Week as a college student. But it wasn’t something that was mainstream.

“I think it was more of a kind of cultural celebration in the early days,” she said. “And so a lot of student groups, I remember as doing programming around the different histories, cultural traditions and issues in the community.”

In May 1990, President George H.W. Bush expanded the designation to the entire month.

In 2009, President Obama changed the name to Asian-American and Pacific Islander Heritage Month. Now, President Biden’s administration refers to it as Asian-American, Native Hawaiian and Pacific Islander Heritage Month.

“As artists and journalists, doctors and engineers, business and community leaders, and so much more, AA and NHPI peoples have shaped the very fabric of our Nation and opened up new possibilities for all of us,” President Biden said in an official Asian-American, Native Hawaiian, and Pacific Islanders Heritage Month proclamation issued Tuesday.

The White House will hold a celebration in Washington on May 13 to commemorate 25 years since the inception of the White House Initiative on Asian Americans, Native Hawaiians and Pacific Islanders.

Asian-American and Pacific Islander advocacy groups have long used the month as a platform to bring resources to underserved communities and educate the public. But, the one-two punch of COVID-19 and assaults on Asian people in the U.S. really gave some a new appreciation for the heritage month’s purpose.

Pre-pandemic, Amber Reed, of Montclair, N.J., didn’t really think about Asian American and Pacific Islander Heritage Month. A Korean-American adoptee who grew up one of few Asian children in rural Michigan, she said she didn’t feel a strong connection to her Asian ancestry.

That changed after the March 2021 Atlanta spa shootings that left eight dead, including six Asian women.

In response to the shootings, Ms. Reed and around 50 others started the nonprofit AAPI New Jersey — originally AAPI Montclair. Their advocacy began with surveys of local schools and other institutions’ recognition of Asian American and Pacific Islander Heritage Month.

The group then quickly organized the Lantern Festival for Justice and Remembrance for May. The Chinese tradition of lighting lanterns became a vehicle to honor victims of hate or injustice, Ms. Reed said. The event is now in its fourth year.

The variety of subjects and cultures feted during Asian-American and Pacific Islander Heritage Month has flourished. There are events happening this month that include more narrow topics, such as a panel on the Asian American Church in Pasadena, Calif. There’s an Asian Comedy Fest in New York. And in Wisconsin, the state will celebrate May 14 as Hmong-Lao Veterans Day, which was signed into law in 2021. Thousands of Hmong-Lao soldiers fought alongside U.S. forces during the Vietnam war.

Many Hmong and Laotian families resettled in Wisconsin.

These heritage month celebrations are helping to erode the notion that the whole population is a monolith, Ms. Umemoto said.