The decennial census is the largest peacetime operation of the U.S. federal government. The Census Bureau hires hundreds of thousands of temporary workers to conduct the decennial census. The magnitude of this temporary workforce influences the national employment situation when enumeration efforts ramp up and when they recede. The impact of decennial census hiring on the headline number of payroll jobs added each month is well established, but previous work has not established how decennial census hiring affects the headline unemployment rate. We link the 2010 Decennial Applicant Personnel and Payroll System data to the 2010 American Community Survey to answer this question. We find that the large hiring surge in May 2010 came mostly from people already employed (40 percent) or from people who were unemployed (33 percent). We estimate that the workers hired for Census 2010 lowered the May 2010 unemployment rate by one-tenth of a percentage point relative to the counterfactual. This one-tenth of a percentage point is within the standard error for the official unemployment rate, and BLS press releases would denote a change in the unemployment rate of 0.1% or less as “unchanged.” We also estimate that relative to the counterfactual, the more gradual changes in decennial census employment influenced the unemployment rate by less than one-tenth of a percentage point in every other month during 2010.