By 1915, city touring had marked significant shifts in the way Americans perceived, organized and moved around in urban environments. Urban tourism became a profitable industry in 1915 as the number of tour agencies, railroad passenger departments, guidebook publishers and travel writers grew at a fast pace. The expense of pleasure tours between 1850 and 1915 meant that only a minority of Americans could experience the luxury of tourism. Many Americans traveled to find work, but few found time for enjoyment of the urban environment. As transportation networks improved, the length of commuting decreased, and income rose. A growing number of Americans were able to afford short vacations by 1915. Still, mass tourism was not possible until after World War II.