Olching was completed on 27 October 1839 and the rail service commenced the following year. At the same time a wood pulp factory opened in Olching, which in turn led to a strong influx of workers. The 20th century The predominantly working class population had a large influence on the social and political culture of Olching during the 20th century. During the Weimar Republic the municipal council was solely dominated by left-wing parties. However, for some of these left-wing politicians, such as SPD-mayor Josef Tauscheck, their political beliefs had serious repercussions due to the rise of the right in Germany in the 1920s and 1930s. Some experienced a great degree of harassment, for others it led to internment in the infamous concentration camps after 1933. Just as in the rest of Germany the National Socialists also gained a large following in Olching in the run-up to and during the Third Reich. During an allied air raid on 22 February 1944, 22 people were killed, including two of the approximately 1000 forced laborers located in and around Olching during the war. After World War II about 5,000 Heimatvertriebene (expellees), mainly from Silesia and Czechoslovakia, arrived in Olching. In 1950 these new citizens made up 25% of the population of Olching and they contributed towards the dynamic development of Olching in the post-war era. The erstwhile rural appearance of Olching has changed over time, as the cityscape of Olching is becoming more and more dominated by businesses and blocks of flats. Many of Olching's citizens use the S-Bahn to commute to work in Munich, which was built for the 1972 Summer Olympics. In 1978 Esting, Geiselbullach, and Graßlfing were merged into the larger community of Olching and this has contributed towards a continuous population growth, especially since the development of the Schwaigfeld area in the early 2000s. Olching was named a city on 19 June 2011. Coat of Arms Olching's coat of arms originates from the year 1951. The swept blue bar in the lower part symbolises the river Amper, which flows through Olching and is of major significance for the town. The reed in the middle reminds that Olching was once marshland; the head of wheat symbolises the agriculture and land cultivation. The upper part displays the chequered blue and white Bavarian standard. Population The current figure (August 2009) for the population of Olching is 24,582. In the past ten years,