Thomas McIntyre Cooley

American judge and legal scholar Thomas McIntyre Cooley (1824-1898) served as a State Supreme Court Justice in Michigan and led the court to a national reputation with a distinguished record. In addition, his book, A Treatise on the Constitutional Limitations Which Rest Upon the Legislative Power of the States of the American Union, written in 1868, became the most widely-read and important work of its day on constitutional law.

Early Life

Thomas McIntyre Cooley was born on January 6, 1824, on a small farm in Attica, New York, in a rural part of western New York state. The son of Thomas and Rachel Cooley, he was part of a large, Protestant family. His father had come from Massachusetts to western New York 20 years earlier, and the Cooleys were a farming family.

Although the family was poor, learning was important to young Cooley. As a child he loved history and literature. He balanced his time between working on his father's farm and going to school. When he could not go to school, Cooley taught himself at home, but he did complete three years of high school. Later, he taught school in order to earn money for his education. As noted in American Biographical History of Self-Made Men, Cooley left the family farm in 1842 and became a lawyer's apprentice to Theron R. Stong in Palmyra, New York.


Settled in Michigan, Became a Lawyer

At the age of nineteen, Cooley moved west. As noted on the Michigan Supreme Court Historical Society website, Cooley had planned to continue his studies in Chicago, but during his travels, he ran out of money. He settled in Adrian, Michigan, in 1843, and finished his law studies in the firm of Tiffany and Beaman. His biography in American Biographical History of Self-Made Men commented that Cooley was a "careful student … quick, through, and methodical."

Soon, there were many changes in Cooley's personal and professional life. In December 1846, he married Mary Horton, and the couple would have six children. Also in that year, he was admitted to the Michigan Bar. As noted in his biography on the Michigan Supreme Court Historical Society website, Cooley began a fast-paced professional life upon his admission to the bar. He worked as a deputy county clerk and later, his biography noted, "worked in two law firms while editing the Adrian Watchtower, serving as court commissioner and recorder for Adrian, and cultivating his 100-acre farm."

As an attorney, the American Biographical History of Self-Made Men, noted, Cooley was known for his "great care and faithfulness, clearness, and logical force." His reputation likely led to his selection by the state legislature to compile the statutes of the state, which he completed in one year. As noted on the Cooley Law School website, after Cooley completed this task in early 1857, he was appointed reporter of the State Supreme Court, a position he would hold until 1864.


Accepted Position as Law Professor

In his biography on the Michigan Supreme Court Historical Society website, it was noted that early in his career, Cooley was offered a number of teaching positions at various law schools around the country, but he declined. In 1859, when a department of law was being organized at the University of Michigan in nearby Ann Arbor, he accepted a position. He would remain at the school as a professor until 1884 and also served as dean of the law department and chair of the history department.

The Cooley Law School website noted that Cooley "taught constitutional law, real property, trust, estates, and domestic property." In addition, he "authored countless articles on legal subjects and wrote several full-length works." Once he began his professional relationship with the University of Michigan, Cooley moved to Ann Arbor permanently. Wilfred Shaw, who once served as general secretary of the Alumni Association and was editor of the Michigan Alumnus, reflected that Cooley's home "was long a center of the intellectual and social life of Ann Arbor."


The State Supreme Court Justice

In 1850, according to the Michigan Supreme Court Historical Society website, Michigan's State Constitution read that circuit court judges would also serve as justices of the State's Supreme Court, serving six-year terms. This plan failed. In 1857, the Michigan State Legislature created a permanent State Supreme Court.

As added by American Biographical History of Self-Made Men, Cooley was appointed to the State Supreme Court in 1864, while serving as the dean of the University of Michigan Law School (as it was now known). He joined colleagues James V. Campbell and Isaac P. Christiancy on the bench. In 1868, Cooley became Chief Justice of the Court, and Benjamin F. Graves joined the Court, filling the Justice position vacated by Cooley. Together, these four men became known as "the Big Four."

As both a justice and chief justice, Cooley faced many challenges as the state of Michigan grew and changed. Yet, as it was noted in his profile in American Biographical History of Self-Made Men, Cooley had an "enviable reputation" and possessed "genial qualities … a delicate sense of honor … and strict integrity." His profile added, "his eminent public services entitle him to rank among the foremost men of Michigan."

One of the best known cases Cooley and the State Supreme Court heard involved the establishment of public high schools. In his book Michigan: A History of the Wolverine State, Willis F. Dunbar explained that the Michigan State Legislature passed an act in 1859 that authorized any school district with more than 200 children to establish a high school. The school board would then put forth a proposal to its residents, who would vote on a tax to support the high school. Some school districts ran into resistance, as their residents believed a primary school education was sufficient.

As told by Bruce A. Rubenstein and Lawrence E. Ziewacz in their book Michigan—A History of the Great Lakes State, a group of Kalamazoo, Michigan, citizens filed suit in 1873. They were opposed to taxes supporting a local high school. The citizens lost, but the decision was ultimately appealed to the State Supreme Court.

On July 21, 1874, the Court voted to uphold the lower court's decision, and Cooley spoke for the majority opinion. Rubenstein and Ziewacz noted that "Cooley's opinion helped convince state residents of the propriety of state-funded education." American Biographical History of Self-Made Men added that "the 'Kalamazoo Case' laid the legal foundation for the growth of high schools not only in Michigan, but in other states. … [T]he case is cited in the major histories of American education."

Cooley wrote many of the opinions for the State Supreme Court, including, as the Cooley Law School website noted, the "People ex rel. Sutherland v. Governor, 29 Mich. 320 (1874), which remains a benchmark in the separation of powers among the three branches of government."

The Michigan Supreme Court Historical Society website noted that during these years, Michigan's State Supreme Court, led by Cooley and the rest of the "Big Four," was soon "recognized throughout the United States as a strong judiciary, ranking with the best in the land. The Court worked with a new Constitution in the formative years of Michigan's statehood. It was instrumental in sharpening judicial procedures and resolving constitutional issues." The professional relationship of the "Big Four" would end in 1875, when Justice Christiancy was elected to the United States Senate.


Cooley the Writer

As noted on the Michigan Supreme Court Historical Society website, Cooley was also known for his literary works. He wrote a number of law articles, manuals, and books, the most famous being A Treatise on the Constitutional Limitations Which Rest Upon the Legislative Power of the States of the American Union. In this book, written in 1868, Cooley was the first to interpret 'due process of law,' mentioned in the Fifth and Fourteenth Amendments to the Constitution, as a means of broadly protecting property and liberty of contract.

Cooley also wrote The Law of Taxation (1876, 4th edition in 1924), Michigan, a History of Governments (1885, rev. ed. 1905), The Element of Torts, and General Principles of Constitutional Law, (2nd edition in 1891) and served as assistant editor of the American Law Register. In one of his writings, he also coined the phrase "A public office is a public trust."


Later Years

Cooley was committed to the ideals of private property, equal rights, and political liberty for all citizens. These influences also led to his intense dislike of special privileges for corporations. As a justice on the Michigan State Supreme Court, Cooley used common law in his opinions to place clear limitations on government power. He did this to keep corporations from influencing the government or violating public trust. He felt a distinct division between public and private activity was necessary.

Cooley retired from the State Supreme Court in 1885, and then, the Michigan Supreme Court Historical Society website noted, "The later part of Cooley's career was played out on a national level. He was placed on a commission to investigate issues involving railroads." During Cooley's time, the railroad companies committed many unfair practices. He believed the separation of public and private spheres of activity would keep the railroads from financing their own development with public credit and tax revenues.

Because of the abuses perpetrated by the railroads, the Interstate Commerce Act became law in 1887. The Interstate Commerce Commission (ICC) was established to enforce the Act. In 1887, U.S. President Grover Cleveland appointed him to the newly-established ICC. He was elected chairman and established the guidelines for the administration of this first important federal regulatory agency. He retired from the commission in 1891.

In his later years, Cooley received honorary degrees (LL.D.) from the University of Michigan, Harvard University, and Princeton. He continued to be highly regarded at the University of Michigan Law School. In 1895, a bronze bust statue of Cooley was placed in the University of Michigan Law Library. Shaw added, "Cooley's great work, with its high scholarship and profound learning, added greatly to the reputation of the University."

After he resigned from the Interstate Commerce Commission, Cooley continued to write legal articles until his death. He died on September 12, 1898, in Ann Arbor, at the age of 74.

The Cooley Legacy

In 1972, Cooley's contributions to law were permanently recognized when "The Thomas M. Cooley Law School" was founded in Lansing, Michigan, the state's capital. Thomas E. Brennan Sr., one of the founders of the law school, as well as its president, commented on Cooley's accomplishments, noting that "Justice Cooley, a law teacher, constitutional scholar, and small town practitioner, combined true scholarship with professional accomplishment, business acumen, and public service."

In addition to the law school, Cooley's legacy lives on in the 21st century. The law school's website noted that Cooley's writings are still cited in court opinions, and legal scholars continue to discuss his interpretations. Papers that Cooley wrote between 1850 and 1898 can also still be found at the University of Michigan Bentley Historical Library. Dunbar perhaps summed it up best when he wrote, "Cooley was the most notable jurist Michigan has ever produced."


American Biographical History of Self-Made Men—Michigan Volume, Western Biographical Publishing Company, 1878.

Cooley, Thomas M., General Principles of Constitutional Law, Weisman Publications, 2 Ed edition, 1998.

Dunbar, Willis F., Michigan: A History of the Wolverine State, William B. Eerdmans Publishing Company, 1995.

Dunbar, Willis Frederick, PhD, Michigan Through the Centuries, Lewis Historical Publishing Company, Inc., New York, 1955.

Jones, Alan, The Constitutional Conservatism of Thomas McIntyre Cooley: A Study in the History of Ideas, Garland Publishing, 1987.

May, George S., Michigan: An Illustrated History of the Great Lakes State, Windsor Publications, Inc., 1987.

Paludan, Phillip, A Covenant with Death: The Constitution, Law, and Equality in the Civil War Era, University of Illinois Press, 1975.

Rubenstein, Bruce A., and Lawrence E. Ziewacz, Michigan—A History of the Great Lakes State, Forum Press, 1981.

Shaw, Wilfred, (General Secretary of the Alumni Association and editor of the Michigan Alumnus), The University of Michigan, Harcourt, Brace, and Howe, 1920.


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"History & Mission," Thomas M. Cooley Law School website, (January 13, 2002).

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"Thomas M. Cooley, 25th Justice," The Michigan Supreme Court Historical Society website, (January 13, 2002).

"Thomas M. Cooley—The Man," Thomas M. Cooley Law School website, (January 13, 2002).

"Welcome from the President," Thomas M. Cooley Law School website, (January 13, 2002).