Located along the Kiskiminetas River, Leechburg was known as a major port of the Pennsylvania Canal. Early in the twentieth century, it had been the site of extensive steel sheet works, foundries, cement plants, and productive coal mines. Leechburg was the first place where natural gas was used for industrial purposes.
As of the census of 2000, there were 2,386 people, 1,109 households, and 645 families residing in the borough. The population density was 5,320.9 people per square mile (2,047.2/km²). There were 1,193 housing units at an average density of 2,660.5/sq mi (1,023.6/km²). The racial makeup of the borough was 97.53% White, 1.26% African American, 0.04% Native American, 0.17% Asian, 0.04% from other races, and 0.96% from two or more races. Hispanic or Latino of any race were 0.67% of the population.
There were 1,109 households out of which 23.4% had children under the age of 18 living with them, 43.2% were married couples living together, 10.7% had a female householder with no husband present, and 41.8% were non-families. 39.1% of all households were made up of individuals and 23.1% had someone living alone who was 65 years of age or older. The average household size was 2.14 and the average family size was 2.85.
In the borough the population was spread out with 21.1% under the age of 18, 6.4% from 18 to 24, 26.2% from 25 to 44, 22.5% from 45 to 64, and 23.7% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 83.7 males. For every 100 females age 18 and over, there were 78.5 males.
The median income for a household in the borough was $27,434, and the median income for a family was $38,785. Males had a median income of $31,250 versus $25,901 for females. The per capita income for the borough was $16,242. About 7.9% of families and 11.6% of the population were below the poverty line, including 13.2% of those under age 18 and 11.0% of those age 65 or over.
Population: 1850: 359 1870: 368 1880: 1,123 1890: 1,921 1900: 2,459 1910: 3,624 1930: 4,489 1940: 4,275 1950: 4,042 1960: 3,545 1970: 2,999 1980: 2,682 1990: 2,504 2000: 2,386