osen as the site of several important congresses and peace treaties: the first congress of Aachen (often referred to as Congress of Aix-la-Chapelle in English) in 1668, leading to the First Treaty of Aachen in the same year which ended the War of Devolution. The second congress ended with the second treaty in 1748, finishing the War of the Austrian Succession. The third congress took place in 1818 to decide the fate of occupied Napoleonic France.
By the middle of the 19th century, industrialisation swept away most of the city's medieval rules of production and commerce, although the entirely corrupt remains of the city's medi�val constitution was kept in place (compare the famous remarks of Georg Forster in his Ansichten vom Niederrhein) until 1801, when Aachen became the "chef-lieu du d�partement de la Roer" in Napol�on's First French Empire. In 1815 after the Napoleonic Wars, the Kingdom of Prussia took over and the city became one of its most socially and politically backward centres until the end of the 19th century. Administered within the Rhine Province, by 1880 the population was 80,000. Starting in 1840, the railway from Cologne to Belgium passed through Aachen. The city suffered extreme overcrowding and deplorable sanitary conditions up to 1875 when the medieval fortifications were finally abandoned as a limit to building operations and new, less miserable quarters were built in the eastern part of the city, where drainage of waste liquids was easiest. In 1880, the Aachen tramway network was opened, and in 1895 it was electrified. In the 19th century and up to the 1930s, the city was important for the production of railway locomotives and carriages, iron, pins, needles, buttons, tobacco, woollen goods, and silk goods.
Aachen was heavily damaged during World War II. The city and its fortified sourroundings were encircled 13 September�16 October 1944 by the US 1st Infantry Division and 3rd Armored Division in conjunction with the US 2nd Armored
