After he left the White House in March of 1893, Harrison did not immediately return home to Indianapolis. He visited the World's Columbian Exposition in Chicago in June 1893 and after the Expo, Harrison returned to his home in Indianapolis. Harrison had been elected a companion of the Military Order of the Loyal Legion of the United States in 1882, and was elected as commander (president) of the Ohio Commandery on May 3, 1893. For a few months in 1894, Harrison lived in San Francisco, California, where he gave law lectures at Stanford University. In 1896, some of Harrison's friends in the Republican party tried to convince him to seek the presidency again, but he declined. He knew that he wouldn't have won the nomination, as he had alienated too many Republicans during his term in office by not being more supportive on doling out patronage properly. When William McKinley won the nomination, Harrison traveled around the nation making appearances and speeches in William McKinley's candidacy for president.
From July 1895 to March 1901 Harrison served on the Board of Trustees of Purdue University. Harrison Hall, a dormitory there, was named in his honor. He wrote a series of articles about the Federal government and the presidency which were republished in 1897 as a book titled This Country of Ours.
In 1896, sixty-two year old Benjamin Harrison got married for the second time. His first wife Caroline died in October of 1892 just before Harrison's election loss to the Cleveland. He shocked members of his family when, in 1896, he married, Mary Scott Lord Dimmick, a woman twenty-five years younger than him. She was a 37 year old widow was the niece and former secretary of his late wife. Harrison's two adult children, Russell, 41 years old at the time, and Mary (Mamie) McKee, 38, strongly disapproved of the marriage and did not attend the wedding. Benjamin and Mary had one child together, Elizabeth, who was born on February 21, 1897.
In 1899 Harrison traveled to Europe to attended the First Peace Conference at The Hague. The Hague Convention of 1899 was the first multilateral treaty that addressed the conduct of warfare. It adopted what was known as the Lieber Code, rules of warfare conduct that had been signed and issued by President Abraham Lincoln on April 24, 1863, for the Union Forces during the Civil War. The Lieber Code was the first official comprehensive codified law that set out regulations for behavior in times of martial law, for protection of civilians and civilian property, and for punishment of military transgression. It dealt with subjects such as treatment of deserters, prisoners of war, and hostages, as well as how to deal with pillaging, partisans, spies, truces and prisoner exchanges. These rules were considered to be an excellent summary of the first customary laws and customs of war in the 19th century. They were adopted by military establishments of other nations. Much of the regulations in the Hague Conventions were borrowed heavily from the Lieber Code.
The conference also included negotiations concerning disarmament, the laws of war and war crimes. A major goal of the conference was the creation of a binding international court for compulsory arbitration to settle international disputes, hoping that this might replace the institution of war. This effort failed. Most of the countries present, including the United States, the United Kingdom, Russia, France, China, and Persia, favored a process for binding international arbitration, but the provision was vetoed by a small group of countries, led by Germany.
In 1897, Harrison took on the job of chief legal counsel for the Republic of Venezuela in their British Guiana boundary dispute with Great Britain. This was a longstanding dispute that had come to a head in 1895. Venezuela hired William Lindsay Scruggs as its lobbyist in Washington, D.C. Scruggs took up Venezuela's argument that British action violated the Monroe Doctrine. Scruggs used his influence to get the US government involved in the dispute. President Grover Cleveland took the position that the Monroe Doctrine not only forbid new European colonies in the western hemisphere, but that it also declared an American interest in any matter within the hemisphere. The key issue in the dispute was Britain's refusal to include the territory east of the Schomburgk Line in the proposed international arbitration. Ultimately Britain backed down and tacitly accepted the US right to intervene under the Monroe Doctrine. This US intervention led to Britain agreeing to accept arbitration of the entire disputed territory. An international trial was agreed upon, to be held in Paris.
Harrison filed an 800-page brief. He traveled to Paris in 1899 for the hearing before the Tribunal of Arbitration, where he spent more than 25 hours in court on Venezuela's behalf. His wife and daughter traveled with him. The tribunal judges included two British arbitrators, one American and one Russian. Harrison was on his feet arguing before the tribunal for over twenty-five hours over the course of five days. In the end, the court found for the British and upheld the British interpretation of where the disputed boundary was. Harrison was embittered by the result. He wrote, "Law is nothing to a British judge it seems when it is a matter of extending British dominion." Although he lost the case, Harrison was praised for his ability as counsel, and for his legal arguments.
Harrison returned home, and soon he experienced health problems. Harrison developed what was thought to be influenza (then referred to as grippe) in February of 1901. He was treated with steam vapor inhalation and oxygen, but his condition worsened. He died from pneumonia at his home in Indianapolis on Wednesday, March 13, 1901, at the age of 67.