Wednesday was supposed to be the great coming together for the 2020 Census. The bureau, city agencies and civic organizations had spent years planning for April 1, the official Census Day.

The week leading up to it was to be filled with rallies, block parties, church events and door-knocking campaigns to urge people to respond and, in some cases, to remind them that the survey does not include the citizenship question that roiled the nation last year and threatened to harm the count.

But the first packets inviting U.S. residents to respond to the decennial count began arriving in mailboxes in mid-March, the very week that the spread of the novel coronavirus sparked a giant shutdown of the country.

Almost overnight, the plans were thrown into chaos. Millions of dollars in New York City subway and bus stop ads would no longer reach residents in a city where few dared to venture out. Religious leaders who had planned to tell their congregations to whip out their mobile phones and respond en masse had shuttered their houses of worship. Public libraries, schools and other key centers of information were now closed.

Since the virus began its gallop across the United States, government and civic groups have worked in overdrive to redirect the enormous get-out-the-count machinery toward the millions sheltering at home. Using texts, phone calls, digital and television ads and even bullhorns, they are scrambling to salvage an operation that has traditionally relied on large gatherings and face-to-face interactions to boost response rates for the once-in-a-decade event.

The hope is to navigate to a sweet spot that allows them to reach every household in the country while keeping residents and their own employees safe, particularly in low-income, minority, immigrant and tribal populations that are difficult to count even in the best of times.

Census data is used to determine a decade’s worth of federal funding along with congressional apportionment and redistricting. And it may be those hit hardest by the pandemic and its economic toll who will suffer most by not being counted, said Rebecca DeHart, chief executive of Fair Count, an Atlanta-based nonprofit focused on achieving an accurate 2020 count.

“I’m extraordinarily worried about the effects that this global pandemic is going to have on the census,” she said. “Communities where joblessness is going to go through the roof, where there’s a strain on hospitals, where children are missing significant amounts of school, if on top of these issues for the next 10 years they are undercounted for things like roads, infrastructure, SNAP, Head Start and public schools, it’s just going to put disenfranchised communities even more squarely behind. . . . We’re in a pretty dire situation right now to make sure everyone gets counted.”

Fair Count had organized local and national events around the census, including a statewide bus tour that would have made more than 60 stops, with DJs and speakers. It had also scheduled meetings with faith leaders, elected officials and Congressional Black Caucus partners. All of that has been upended.

Some of the forums and meetings have moved to online platforms such as Zoom and Facebook Live, including a “Sisters for the Census” event last week with Stacey Abrams, the organization’s founder, and National Council of Negro Women President Johnnetta Cole. Fair Count has also inserted advertising into an app where people go to check on their food stamp allotment. “We’re really trying to think outside the box,” DeHart said.

One silver lining census officials and their partners are banking on is the bureau’s switch to asking most people to respond digitally, which allows many people to fill out the form online from home.

The bureau has also produced a real-time online map that can tell, down to the census tract, what percentage of a city, county, state or the nation has responded. So far, about 35 percent of the nation has responded, which is on track with where the bureau had estimated the country would be at this point, said Stephen Buckner, the bureau’s assistant director of communications. The bureau has redirected advertising from public arenas to digital, radio and television, and it plans to swap out some of its original advertising with new content commensurate with the pandemic.

“We had ads showing people at outdoor activities or having dinner together out at a restaurant,” Buckner said. “A lot of that imagery is not the world we’re living in today.”

The map has allowed some organizers to measure the effect of their efforts.

In Philadelphia, Philly Counts, organized by the city’s mayor, had planned to do about 200,000 door hangings with information about filling out the form. The group was able to do 75,000 before the shelter-in-place directives stopped that operation. But looking at the response map, which is updated daily, they were able to see a 3 to 5 percent boost in tracts that had received the door hangings.

“On one hand, that’s been great because we knew what we were doing; on the other hand, it’s been heartbreaking,” said Stephanie Reid, the group’s executive director. “We’ve tried to quickly turn our ship. We purchased a program where we can run large organized conference calls, and we’ve been holding two weekly with our partners.”

The group has also ramped up its message on social media and phone banking. “Honestly, people are home, and for the most part, people are answering their phones more than they normally would,” Reid said.

Still, it remains to be seen whether this will be enough to mitigate the effects of the pandemic, especially in communities where people are worried about getting food or staying in their homes, she said. “It’s hard to imagine a scenario where the census is not impacted by this. The question is: How much and what we need to do to ensure that we get a complete and accurate count?”

In New York City, the mayor’s office had partnered with 157 community organizations and disbursed $19 million to them; 500 events had already taken place, with hundreds more planned, including town halls, rallies, and census “fun days” in hard-to-count communities. Over 300 pop-up centers with computer terminals were set to give access to the third of New Yorkers who don’t have access to broadband.

Now, with the number of coronavirus cases exceeding 40,000 and hospitals overwhelmed, Census Day has been all but drowned out, and the group has scrambled to refashion its approach.

“We did have a signed contract to do subway ads, and we were able to work to claw the money back and convert it to TV and digital ad buys,” said Julie Menin, director of Census for NYC, adding that more than 700 volunteers have been doing one-to-one phone and text banking, reaching more than 1 million New Yorkers so far.

The group is particularly pushing ads they already had that talk about the connection between census data and medical services.

“Funding for hospitals, funding for health care is determined by the census,” Menin said. “It’s really important that people know that and feel like this is something they can do. … With so many things being out of control and our city being in crisis, there’s one thing that we feel like they can control — being counted for hospitals, for health care and for so many vital services that they will desperately need.”

For people in tribal areas, the inability to congregate in person is particularly problematic because many people don’t have standard mailing addresses, meaning their packets are typically delivered in person. The bureau has delayed that operation by at least two weeks.

Tribal areas may still set up mobile hotspots and some in-person interactions, said James Tucker, vice chair of the National Advisory Committee to the Census Bureau, adding that many of them are in closed communities where people are already interacting.

William Frey, a Brookings Institution demographer and a professor at the University of Michigan’s Institute for Social Research and Population Studies Center, said the fact that the count had planned for a largely digital operation might allow it to weather the coronavirus relatively well. “If this had happened 10 years ago it would be much worse,” he said, adding that even with delays, there will still be time to complete the count if the country opens back up in May or June. “It’s not the death knell for the census,” he said.

In the meantime, local organizers are getting creative. In the District, palm cards with information on the census will be tucked into the school lunches and senior meals the city gives out.

In nearby Mount Ranier, Md., whose diverse population suffered an undercount in 2010, Mayor Malinda Miles (D) had planned to bus people in to libraries and other places where computers would be set up for people to fill out forms. “We were going to give them food and little trinkets,” she said.

Instead, she has undertaken her own grass-roots effort, sending daily emails to Listserves and updating four Facebook pages she maintains.

On Census Day she plans to drive around the city of 9,000 people with a bullhorn three or four times during the day, reminding residents to fill out their forms.

“Mount Rainier cannot afford to be undercounted — do you want these parks to stay open and clean? How about social services to my seniors? Do we need day care?” she said.

“My message is, ‘This too shall pass, and so will the census if we don’t get this done.’ ”