What does In God We Trust mean on the dollar bill?

Answer 1

The same thing that it means on all US Coins and Paper Money - that the US is generally a religious nation and puts its faith in God.

The phrase's use has had a checkered history, often in times of national peril. It was first put on the 2¢ piece in 1864, during the Civil War, as an expression of faith during that terrible conflict. It was soon added to several other coins but it took until 1938 for it to appear on all circulating denominations.

During that long period it was never printed on paper money, though. But in 1955, during the Cold War, Congress passed a law mandating that it appear on paper money as well. The motto's use was seen as a way to express the country's faith in the face of the very real threat of Soviet communism which was officially atheistic. By 1957 it had been added to $1 bills and was rapidly put on all other denominations.

Unfortunately its presence has been a matter of contention between groups at the extreme ends of the political spectrum, with some people claiming that it violates the separation of church and state, while other, more prevalent organizations push for it to be displayed more prominently and in more places while spreading rumors that the phrase may be abolished at any moment. For the vast majority, though, it's not a major consideration.