Final answer:
The United States last had a budget surplus in the year 2000. The budget returned to deficits thereafter, notably increasing during the 2008-2009 recession.
Step-by-step explanation:
The last time the United States had a budget surplus was around the year 2000. This is informed by multiple sources and figures stating that there has been a consistent budget deficit for over 30 years with the sole exceptions occurring in 1999 and 2000. After these years, the United States reverted back to running a budget deficit, with particularly large deficits occurring during the Great Recession of 2008-2009.