At the outset of America's involvement in World War I in 1917, the Carnegie Endowment trustees unanimously declared, "the most effective means of promoting durable international peace is to prosecute the war against the Imperial Government of Germany to final victory for democracy."
In December 1918, Carnegie Endowment Secretary James Brown Scott and four other Endowment personnel, including James T. Shotwell, sailed with President Woodrow Wilson on the USS George Washington to join the peace talks in France.

Carnegie is often remembered for having built Carnegie libraries, which were a major recipient of his largesse.
The libraries were usually funded not by the Endowment but by other Carnegie trusts, operating mainly in the English-speaking world.
However, after World War I the Endowment built libraries in Belgium, France and Serbia in three cities which had been badly damaged in the war.
In addition, in 1918, the Carnegie Endowment for International Peace (CEIP) began to support a library special collection called the International Mind Alcove program which aimed to change people's global perspective, fostering an 'international mind' in America as well as in other countries.
The foundational idea behind the program was that internationalism would replace nationalism and people would be more inclined toward peace once they had a greater understanding of different cultures.
This program was established in 1918 after World War I and by 1924 had grown significantly, “with eighty-one collections in the US and twenty-two in other countries”.
After the US entered World War II, the International Mind Alcove collections were “repackaged” to support the state, although the collection didn’t change.
After World War II, the United Nations began promoting the idea of internationalism, eventually leading the CEIP to end the International Mind Alcove program.
Early in the 1950s, the CEIP came under scrutiny by the US Congress for subversive activities during the anti-communist atmosphere at that time.
Mainly, the Alcove project and the books that were disseminated under this international program were the focus of the investigation.
The books were reviewed by a political science professor, who concluded that the books did not “promote the national interest”.
At that point it was irrelevant since the program was being eliminated, but the findings supported the charge of subversion, stating the idea of internationalism contributes to the “degradation of American ‘nationalism’”.
By 1958 the CEIP had ended funding for the program, ending its mission, completely unrelated to the Congressional investigation.

On July 14, 1923, the Hague Academy of International Law, an initiative of the Endowment, was formally opened in the Peace Palace at The Hague.

The Peace Palace had been built by the Carnegie Foundation (Netherlands) in 1913 to house the Permanent Court of Arbitration and a library of international law.

In 1925, Nicholas Murray Butler succeeded Elihu Root as president of the Endowment.
For his work, including his involvement with the Kellogg–Briand Pact, Butler was awarded the Nobel Peace Prize in 1931.

In November 1944, the Carnegie Endowment published Raphael Lemkin's Axis Rule in Occupied Europe: Laws of Occupation—Analysis of Government—Proposals for Redress.
The work was the first to bring the word genocide into the global lexicon.
In April 1945, James T. Shotwell, director of the Carnegie Endowment's Division of Economics and History, served as chairman of the semiofficial consultants to the U.S. delegation at the San Francisco conference to draw up the United Nations Charter.
As chairman, Shotwell pushed for an amendment to establish a permanent United Nations Commission on Human Rights, which exists to this day.

In December 1945, Butler stepped down after twenty years as president and chairman of the board of trustees.
Butler was the last living member of the original board selected by Andrew Carnegie in 1910.
John Foster Dulles was elected to succeed Butler as chairman of the Board of Trustees, where he served until fellow
At the outset of America's involvement in World War I in 1917, the Carnegie Endowment trustees unanimously declared, "the most effective means of promoting durable international peace is to prosecute the war against the Imperial Government of Germany to final victory for democracy." In December 1918, Carnegie Endowment Secretary James Brown Scott and four other Endowment personnel, including James T. Shotwell, sailed with President Woodrow Wilson on the USS George Washington to join the peace talks in France.
Carnegie is often remembered for having built Carnegie libraries, which were a major recipient of his largesse. The libraries were usually funded not by the Endowment but by other Carnegie trusts, operating mainly in the English-speaking world. However, after World War I the Endowment built libraries in Belgium, France and Serbia in three cities which had been badly damaged in the war. In addition, in 1918, the Carnegie Endowment for International Peace (CEIP) began to support a library special collection called the International Mind Alcove program which aimed to change people's global perspective, fostering an 'international mind' in America as well as in other countries. The foundational idea behind the program was that internationalism would replace nationalism and people would be more inclined toward peace once they had a greater understanding of different cultures. This program was established in 1918 after World War I and by 1924 had grown significantly, “with eighty-one collections in the US and twenty-two in other countries”. After the US entered World War II, the International Mind Alcove collections were “repackaged” to support the state, although the collection didn’t change. After World War II, the United Nations began promoting the idea of internationalism, eventually leading the CEIP to end the International Mind Alcove program. Early in the 1950s, the CEIP came under scrutiny by the US Congress for subversive activities during the anti-communist atmosphere at that time. Mainly, the Alcove project and the books that were disseminated under this international program were the focus of the investigation. The books were reviewed by a political science professor, who concluded that the books did not “promote the national interest”. At that point it was irrelevant since the program was being eliminated, but the findings supported the charge of subversion, stating the idea of internationalism contributes to the “degradation of American ‘nationalism’”. By 1958 the CEIP had ended funding for the program, ending its mission, completely unrelated to the Congressional investigation.
On July 14, 1923, the Hague Academy of International Law, an initiative of the Endowment, was formally opened in the Peace Palace at The Hague. 
The Peace Palace had been built by the Carnegie Foundation (Netherlands) in 1913 to house the Permanent Court of Arbitration and a library of international law.
In 1925, Nicholas Murray Butler succeeded Elihu Root as president of the Endowment. For his work, including his involvement with the Kellogg–Briand Pact, Butler was awarded the Nobel Peace Prize in 1931.
In November 1944, the Carnegie Endowment published Raphael Lemkin's Axis Rule in Occupied Europe: Laws of Occupation—Analysis of Government—Proposals for Redress. The work was the first to bring the word genocide into the global lexicon. In April 1945, James T. Shotwell, director of the Carnegie Endowment's Division of Economics and History, served as chairman of the semiofficial consultants to the U.S. delegation at the San Francisco conference to draw up the United Nations Charter. As chairman, Shotwell pushed for an amendment to establish a permanent United Nations Commission on Human Rights, which exists to this day.
In December 1945, Butler stepped down after twenty years as president and chairman of the board of trustees. Butler was the last living member of the original board selected by Andrew Carnegie in 1910. John Foster Dulles was elected to succeed Butler as chairman of the Board of Trustees, where he served until fellow 
Carnegie Endowment for International Peace