A career Foreign Service Officer, she was the United States Ambassador to Norway from 1964 to 1969 under President Lyndon Johnson.

In the 1930s, Pearl Tibbetts published a novel, Land Under Heaven, based on her family's history in Arooostook County, Maine.

[6] After graduating from high school in 1937, Tibbetts attended Wheaton College in Norton, Massachusetts, where she majored in history, and was involved in student government and basketball.

At Wheaton, she was a member of the honor society Phi Beta Kappa, and graduated summa cum laude in 1941.

[6][5] Tibbets then enrolled in a PhD program at Bryn Mawr College, where she specialized in British political history.

[6] Tibbetts was sworn into the Foreign Service in 1949, and her first assignment was in the Political Affairs section of the Embassy of the United States, London.

One of her major tasks over the next few years was to monitor British policy towards Africa, especially the debate over whether or not to create a Central African Federation.

Tibbetts encouraged the U.S. government to support the British decision, and thus helped facilitate American involvement in the Federation.

While serving at the embassy in London, Tibbetts attended a conference in Mozambique, visiting several parts of Africa on her journey.

In one noteworthy message, she warned her colleagues in Washington about the potential for Congolese union leaders such as Patrice Lumumba to play a key role in future nationalist movements.

[7] After two years working in the State Department's office of European affairs, in 1959 Tibbetts joined the staff of the International Cooperation Administration and served a two-year stint.