In the X. Y.Z affair, these letters stood for: Three nations that secretly wanted independence.

Three French men that did not want to be named when they bribed US diplomats.

The early CIA and FBI operating in secret in Virginia and Georgia.

Three French men that did not want to be named when they bribed US diplomats.

Explanation:

As early as the autumn of 1796, the United States' relations with France began to deteriorate rapidly. After the unilateral dissolution of the Union with the United States in 1778, France began aggression against American merchants in the Caribbean and Atlantic. France's continuing aggression at sea and its apparent attempts to undermine American policy with revolutionary propaganda and bribery led the two great powers to declare war, especially at sea.

In May 1797, US President John Adams decided that, despite opposition from the Federalist Party, he would send three diplomats to Paris to seek a negotiated solution. Six months later, a message arrived in Philadelphia that the French foreign minister had informed American diplomats through intermediaries that negotiations could only take place if he was paid a solid sum.  The President published the delegation's report, in which the French agents were designated by the letters X, Y and Z (from which the informal name of the document and the entire incident came from), stirring up a storm of anti-French sentiment in American society.

answer: they arrived in new york.