Even though Mckeesport has lost well over half of it's population since it's peak in 1940 it's still the largest city on the Monongahela River between Pittsburgh and Morgantown West Virginia. Other cities on the Monongahela have in many cases lost even greater percentages of their population. Mckeesport's peak population was 55,355 (1940). Today it's home to 19,686 people (2012). Mckeesport had many steel related plants but was not home to any of the massive integrated mills that operated in the Steel Valley. The largest mill in the city was the National Tube Works which at it's peak in the 1940s employed as many as 10,000 people. Because of the importance of the tube works some called Mckeesport "Tube City", apparently. The National Tube Works plant has been entirely demolished. Mckeesport was the commercial center for the region and as such had an extensively developed downtown business district. Today that district is dotted with abandoned buildings and empty lots.