Before the unification of Italy in 1870, when the Papal States were still a temporal sovereignty, U.S.A. was represented diplomatically at the Papal Court. The first charge d'affaires was appointed in 1848. A minister resident was appointed in 1854. After the break up of the Papal States in 1870 the U.S. minister was withdrawn.
Diplomatic relations remained in abeyance until 1893, when Leo XIII appointed Mgr. Francesco Satolli as Apostolic Delegate to the United States. The post of Apostolic Delegate is an important one, ranking with a nunciature of the first class, such as established in Vienna or Lisbon. The Delegate is invariably raised to the Cardinalate and is given power to decide appeals in the country in which he is delegate by definitive sentence, that is, there can be no appeal to Rome after appeal to the Delegate.
Pope Leo, in establishing an Apostolic Delegate, made clear his reasons. " By this action, as we have elsewhere intimated, we wished, first of all, to certify that in our judgement and affection, America occupied the same place and rights as other states, however powerful and imperial."
As America has no diplomatic relations with the Holy See, the Apostolic Delegate does not hold the title of Envoy Extraordinary, by which title a delegate is accredited to the government of such countries as Colombia, Peru, Bolivia.