A man of strong and independent convictions and, on the whole, a strict constructionist, Harlan became known as a dissenter. In the "insular cases" (1901) he protested against the decision that denied the residents of the new U.S. possessions the national benefits of the Constitution. He upheld the police power of the states, dissented in the civil-rights cases (1883) and the income-tax case (1894), and argued that the court had no right to read the word unreasonable into the Sherman Act in the decisions against the Standard Oil and American Tobacco trusts. A firm defender of civil liberties and civil rights, Justice Harlan dissented vigorously in Plessy v. Ferguson (1896), in which the Supreme Court enunciated the "separate but equal" doctrine justifying segregation. In 1893, President Benjamin Harrison appointed him to the tribunal to settle the Bering Sea Fur-Seal Controversy (see under Bering Sea) at Paris.
See the memoirs of his wife, M. S. Harlan, Some Memories of a Long Life, 1854-1911 (2002); F. B. Clark, The Constitutional Doctrines of Justice Harlan (1915); F. Latham, The Great Dissenter (1970).
There were 2,204 households out of which 31.1% had children under the age of 18 living with them, 56.6% were married couples living together, 8.9% had a female householder with no husband present, and 32.0% were non-families. 28.9% of all households were made up of individuals and 16.3% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.88.
In the city the population was spread out with 25.1% under the age of 18, 6.1% from 18 to 24, 24.2% from 25 to 44, 22.4% from 45 to 64, and 22.3% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 90.9 males. For every 100 females age 18 and over, there were 85.4 males.
The median income for a household in the city was $35,899, and the median income for a family was $45,888. Males had a median income of $31,365 versus $19,671 for females. The per capita income for the city was $17,514. About 5.3% of families and 7.0% of the population were below the poverty line, including 7.3% of those under age 18 and 9.4% of those age 65 or over.