Territorial Growth of the City of Pittsburgh
Territory Annexed Entry Date Area Annexed (Sq. Miles) Total Area (Sq. Miles)
Borough of Pittsburgh March 5, 1804 0.50 0.5
City of Pittsburgh March 18, 1816 0.5
Northern Liberties Borough March 1, 1837 0.17 0.7
City's District 8/17 July 7, 1845 0.17 0.8
Part of Pitt Township November 4, 1846 0.8
Part of Pitt Township December 4, 1846 0.93 1.8
Part of Pitt Township December 12, 1846 1.8
Remainder of Pitt Township June 30, 1868 1.8
Peebles Township June 30, 1868 1.8
Liberty Township June 30, 1868 1.8
Collins  Township June 30, 1868 21.34 23.1
Oakland  Township April 2, 1872 23.1
Lawrenceville  Boro April 2, 1872 23.1
Union  Township April 2, 1872 23.1
Temperanceville Boro April 2, 1872 23.1
Mount Washington Boro April 2, 1872 23.1
West Pittsburgh Boro April 2, 1872 23.1
Monongahela Boro April 2, 1872 23.1
South Pittsburgh Boro April 2, 1872 4.19 27.3
Allentown Boro December 1, 1894 27.3
Birmingham Boro December 1, 1894 27.3
East Birmingham Borough December 1, 1894 27.3
St. Clair Borough December 1, 1894 27.3
Brushton Boro December 1, 1894 0.45 27.8
Beltzhoover Boro March 1, 1898 0.30 28.1
Elliott Boro January 2, 1905 0.32 28.4
Esplen Boro January 8, 1906 0.28 28.6
Sterett Township January 8, 1906 0.48 29.1
Montooth Boro January 7, 1907 0.11 29.2
Sheraden Boro November 21, 1907 0.97 30.2
City of Allegheny December 6, 1907 8.07 38.3
West Liberty Boro January 6, 1908 2.74 41.0
O'Hata Township October 30, 1908 0.32 41.3
Beechview Boro Januayr 4, 1909 0.33 41.7
Part of Union Township January 4, 1909 0.09 41.8
Part of Baldwin Township January 1, 1912 0.24 42.0
Part of Ross Township December 19, 1916 0.02 42.0
Spring Garden Boro January 5, 1920 0.19 42.2
Part of Penn Township June 28, 1920 0.00 42.2
Part of Chartiers Township October 4, 1920 0.02 42.2
Rmeainder of Chartiers Township January 1, 1921 3.42 45.7
Part of Reserve Township October 31, 1922 0.25 45.9
St. Clair Boro January 1, 1923 0.97 46.9
Parts of Lower St. Clair Township February 7, 1924 0.08 47.0
Part of Swissvale Boro November 27, 1925 0.03 47.0
Carrick Boro January 3, 1927 1.59 48.6
Knoxville Boro January 3, 1927 0.30 48.9
Westwood Boro January 3, 1927 0.30 49.2
Union Township January 2, 1928 0.94 50.1
Part of Ross Township June 29, 1928 0.06 50.2
Hays January 7, 1929 0.74 50.9
Part of Mifflin Township February 15, 1929 0.92 51.8
Part of Ross Township April 22, 1929 0.03 51.9
Part of Ross Township April 25, 1929 0.13 52.0
Part of Ross Township June 3, 1929 0.01 52.0
Part of Ross Township July 1, 1929 0.00 52.0
Part of Mifflin Township July 22, 1929 0.00 52.0
Part of Penn Township January 2, 1930 0.03 52.1
Part of Penn Township January 22, 1930 0.02 52.1
Overbrook Boro January 6, 1930 1.23 53.3
Part of Baldwin Township January 5, 1931 0.08 53.4
Part of Mifflin Township February 27, 1931 0.76 54.1
Part of Reserve Township March 20, 1931 0.15 54.3
Part of Baldwin Township December 1, 1947 0.06 54.4
Part of Ross Township April 28, 1948 0.02 54.4
Part of Baldwin Township February 5, 1951 1.08 55.5
Part of Baldwin Township March 13, 1951 0.04 55.5
Part of Robinson Township August 19, 1955 0.03 55.5
Source: Office of the Pittsburgh City Controller