During the late nineteenth century, John Sherman was a prominent United States Senator and Secretary of the Treasury from Ohio.

Sherman was born on May 10, 1823, in Lancaster, Ohio. He was William T. Sherman's younger brother. John Sherman's father died when John was only six years old. Several of his siblings were placed for adoption, but his mother managed to support and raise John. He first attended common schools in Lancaster. From 1831 to 1835, Sherman lived with his father's cousin in Mount Vernon, Ohio, where he received some additional schooling and worked in his guardian's store. In 1835, he returned to Lancaster and enrolled in the Homer (also reported as the Howe) Academy, a private school in Lancaster. After remaining at this institution for two years, Sherman decided to leave school and forego college. He taught himself surveying and accepted a position as a rodman with an engineering company. From 1837 to 1839, Sherman worked on improvements for the Muskingum River. The Panic of 1837 caused the Ohio legislature to scale back funds for the project, and Sherman found himself unemployed in 1839.

Sherman then began to study the law under his brother Charles, who had a legal practice in Mansfield, Ohio. John was admitted to the Ohio bar on his twenty-first birthday. He entered into practice with his brother and became a well-respected trial lawyer. He also began to diversify his economic interests, engaging in the lumber industry in Michigan and investing in a woodworking business in Mansfield. Due to these and other smart investments, Sherman's estate was valued at more than two million dollars upon his death.

It was during the 1840s when Sherman embarked upon a political career. He was a staunch supporter of the Whig Party and served as this group's secretary at the party's national convention in 1848. Sherman supported the Compromise of 1850, hoping to settle the differences between the North and South peacefully. In 1854, he staunchly opposed the Kansas-Nebraska Act, because it repudiated the Missouri Compromise. He quickly allied himself with the Fusion Party, a precursor to the Republican Party. He won election to the United States House of Representatives this same year. In Congress, Sherman was an outspoken critic of President James Buchanan and his policy on the Kansas Territory's admittance to the Union. Sherman argued that the federal government needed to send soldiers to the territory to end "Bleeding Kansas" and to ensure that residents could exercise their right to the elective franchise.

Sherman was reelected to the House of Representatives in 1856 and 1858. In his second and third terms in office, Sherman became expert on fiscal matters and encouraged the federal government to reduce expenditures. In this capacity, Sherman helped the nation recover from the Panic of 1857. He also became a strong supporter of tariffs to protect American industries and to help finance the federal government.

In 1860, Ohio voters reelected Sherman to the House of Representatives. He had reason to believe that his colleagues in the House were about to elect him Speaker, when the Ohio legislature selected Sherman to become one of Ohio's two United States senators. Sherman was to fill a vacancy created by Salmon Chase's appointment as Secretary of the Treasury. Sherman agreed to take the office. During the American Civil War, Sherman was a staunch supporter of President Abraham Lincoln and of the Union. He helped organize a brigade of volunteers from Mansfield, Ohio. Sherman even contemplated resigning his office to enlist in the Union army, but he determined that his services as a politician were in greater need than as a soldier. The senator played a major role in helping the federal government finance the war effort. He was a staunch supporter of the Legal Tender Act of 1862, which allowed the federal government to issue paper currency to pay certain types of debts, and was instrumental in securing its passage through Congress. In 1863, Sherman introduced the National Bank Act. This act worked hand in hand with the Legal Tender Act, providing the federal government with all of the same powers as private and state banks. Sherman hoped to eliminate state and private currency, providing the United States with a single, stable monetary system.

During Reconstruction, Sherman was a moderate Republican, although he usually sided with the policies of the Radical Republicans. Sherman supported the Fifteenth Amendment, enfranchising African-American men, but he opposed the Radicals' desire to disenfranchise former Confederates. He opposed many of President Andrew Johnson's more lenient policies toward the South, although Sherman eventually acknowledged years after the fact that Johnson's conciliatory approach would have reunited the nation together much more quickly. Sherman did vote to remove Johnson from office in the president's impeachment trial.

Sherman remained in the United States Senate until 1877, when President Rutherford B. Hayes appointed him Secretary of the Treasury. As secretary, Sherman encouraged the federal government to pay holders of United States currency the value of the paper money in gold coin. Sherman wanted to assure the American people and foreign countries that the United States could and would honor its obligations. Sherman's fiscal policies succeeded in establishing a sound currency. By 1878, Sherman had succeeded in reducing the amount of paper currency in circulation to the exact amount of gold in the United States Treasury.

Upon the election of James Garfield as president of the United States in 1880, Sherman reentered the United States Senate. His greatest contribution during this era was his authoring of the Sherman Anti-Trust Act. This legislation authorized the federal government to break up any organizations that restrained competition. The federal government utilized this legislation throughout the late 1800s and the 1900s to break up monopolies, including that of the Standard Oil Company in 1911. More commonly, the government also restricted unions with this legislation.

In 1897, President William McKinley appointed Sherman as Secretary of State. These two men quickly developed a difference of opinions on United States expansion. Sherman opposed the acquisition of new territory, while McKinley supported it. Sherman objected to the Spanish-American War and resigned as Secretary of State a week after the United States Congress declared war. Sherman returned to Ohio, where he experienced declining health and mental faculties. He died on October 22, 1900.