Washington Dulles International is the busiest airport in Washington DC
Heathrow Airport.
Heathrow, near London, is the busiest airport in Britain. It is also the busiest international airport in the world.
Heathrow (EGLL) is presently the busiest.
London's Heathrow airport is the busiest.
All of the busiest airports in the world have international flights, so the busiest airport with international service would technically be Hartsfield-Jackson Airport in Atlanta. However, as with most airports in the US, most passengers are domestic. The world's busiest airport by international passengers is London Heathrow.
Hartsfield-Jackson Atlanta International Airport has been the world's busiest passenger airport since 1998.
Hartsfield-Jackson International Airport located in Atlanta is the world's busiest airport. It has been the world's busiest airport since 2000.
London Heathrow is the UK's largest airport.
Dubai
Yes
O'Hare