How the Party at the Mailbox efforts in 2020-2024 led by Black Girls Vote used celebrations of community to increase voter turnout Black voters continue to transform America's electoral landscape and can play a powerful role in determining the outcome of elections. In Party at the Ballot Box, Melissa R. Michelson, Stephanie L. DeMora, and Sarah V. Hayes explore the impact of celebratory voter mobilization campaigns led by Black-led organizations on Black turnout, particularly as more states embrace voting-by-mail. Focusing on the Party at the Mailbox (PATM) initiative, coordinated by Black Girls Vote, Michelson, DeMora, and Hayes underscore what, exactly, motivates Black voters to show up to the polls. Using community-based informational and celebratory packages of materials, and with a mixed methods approach that includes randomized controlled trials, surveys, interviews, and focus groups, they show us how the PATM pilot increased Black turnout in Baltimore by double digits in the 2020 primaries. Despite voting by mail while sheltering in place, PATM made voters feel part of something bigger than themselves-that they were voting as a community. The successful pilot led to further PATM efforts in Atlanta, Baltimore, Detroit, Richmond, and Philadelphia between November 2020 and November 2024. Ultimately, the authors argue that Black Americans vote as a celebration of community, and that cultivating that sense of community is an effective means of increasing Black voter turnout. With a foreword by Nykidra Robinson, founder of Black Girls Vote, Party at the Ballot Box provides insights into Black voter turnout and its larger implications.