The U.S. federal government experienced its longest shutdown in history, lasting 35 days from December 22, 2018, to January 25, 2019. This unprecedented event stemmed from an impasse between President Donald Trump and Congress over his demand for $5.7 billion in federal funds to build a wall on the U.S.–Mexico border. As a result, approximately 800,000 federal employees were furloughed or worked without pay, affecting about a quarter of government operations and costing the American economy an estimated $11 billion.
Initially, the Republican-controlled Senate passed a funding bill without wall money, but President Trump, facing criticism from right-wing media, refused to sign any bill lacking his desired funding. The standoff intensified after Democrats gained a House majority in January 2019, consistently passing bills without wall funding, which Trump and Senate leader Mitch McConnell blocked. The shutdown ultimately concluded on January 25, 2019, when Trump endorsed a temporary funding bill after critical disruptions to air travel were caused by unpaid air traffic controllers taking sick leave. Though Congress later approved $1.375 billion for border fencing, Trump, still unsatisfied, declared a national emergency to secure additional funds for his wall.