The European hotel is an invention or development of the earlier nineteenth century. The hotel as we understand the term today — as a business in the service sector that offers travelers standards of overnight accommodations and entertainment beyond the necessary — was first seen in the United States with the opening of Barnum's City Hotel in Baltimore (1825) and the famous Tremont Hotel in Boston (1829). Not long after, European entrepreneurs started building their own modern hotels, following the standards for comfort, luxury, and service that their American colleagues had set, thus effectively introducing a new kind of commercial hospitality to the European continent. The opening of the Badischer Hof in Baden-Baden (1836) was the beginning of the fast-developing modern hotel industry in the German-speaking countries that saw its peak in the years preceding the First World War. In the nineteenth century, a growing clientele ranging from the traveling aristocracy to middle-class families who were increasingly able to enjoy leisure and time away from home powered the newly emerging tourist industry. This brought about phenomena such as travel agencies (Thomas Cook, an English Baptist Minister, started his British agency in 1841 with his first organized train trip from Leicester to Loughborough, while Carl Stangen imitated the British model in Berlin beginning in 1854), resort hotels in formerly under-developed or under-explored areas, and the internationalization of leisure culture. Its most glamorous and obvious expression might be the grand hotel culture of the pre-war years.