The first passport conference was held in Paris in 1920, under the auspices of the League of Nations (the predecessor of the United Nations). Part of the Committee on Communication and Transit's aim was to restore the pre-war regime of freedom of movement.

Indeed, for much of the 19th century, as an International Labour Organisation report stated in 1922:

Migration was generally speaking, unhindered and each emigrant could decide on the time of his departure, his arrival or his return, to suit his own convenience.

But World War I brought harsh restrictions on freedom of movement.

In 1914, warring states of France, Germany, and Italy were the first to make passports mandatory, a measure rapidly followed by others, including the neutral states of Spain, Denmark, and Switzerland.