Hundreds of billions in federal money. Seats in the U.S. House. Boundaries of voting districts.

It’s all determined by the number of people living in each state and local community in the United States as of April 1, 2020.

If people do not respond to the census forms they get every 10 years, depressed population counts mean states and communities lose out on “a lot of money and power,” said Fernando Armstrong, director of the U.S. Census Bureau’s Philadelphia Regional Office.

The bureau will attempt to count every person residing in the country. And to do that, communities have to change the minds of residents who don’t think filling out the census form is worth their time. A new challenge for governments this year is reassuring people that the information they provide is confidential as the Trump administration works to add a citizenship question to the census form.

Communities across the country and the region — including Philadelphia; Harrisburg; and Mount Holly, Burlington County — will hold rallies Monday to kick off outreach efforts to make sure all their residents are counted in the 2020 Census.

Monday marks a one-year countdown until Census Day — April 1, 2020 — the reference date by which the Census Bureau measures the U.S. population. Although people will be able to fill out their census questionnaires in March 2020 and after April 1, 2020, a baby born on April 2, for example, will not be counted in the 2020 Census.

Philadelphia receives more than $3 billion in federal money each year based on census counts. Pennsylvania gets about $2,100 in federal funds per resident, and New Jersey brings in about $1,960, according to a 2017 report by the George Washington Institute of Public Policy.

At a 9:45 a.m. event at the National Constitution Center, Mayor Jim Kenney plans to introduce members of the city’s Complete Count Committee — which will oversee the city’s census efforts — and to convene the group’s first meeting. At the state capitol at 10:30 a.m., Gov. Tom Wolf’s administration will lay out plans for Pennsylvania’s Census 2020 Complete Count Commission for the coming year.

New Jersey’s secretary of state, Tahesha Way, will travel to the Burlington County Lyceum of History and Natural Sciences in Mount Holly — one of three stops on her 2020 Census promotion tour — for a 6 p.m. rally. She’ll be joined by community groups; Mayor Jason Jones; county and state politicians; and members of the Rancocas Valley Alumnae Chapter of Delta Sigma Theta Sorority Inc., a sponsor of the event.

The rally will “highlight the value and benefit and usefulness” of the census and focus on some of the communities that are traditionally hard to count, said Diana Rogers, a member of the chapter’s social action committee.

“We are trying to ensure that the residents of Burlington County are counted accurately and that there is a complete count,” she said.