This card was sent in 1918. Note the cancellation stamp, which says "food will win the war." I'm going to have to think about that one for awhile. The sender affixed twice as much postage as was needed; postal rates had been increased during the war, but only for letters. The cost of mailing a postcard remained at one cent until 1952 when the rate was raised to two cents.
Washington's streetcar service was established in 1862. As in many other cities throughout America and around the world, the first streetcars in Washington D.C. were horse drawn. There was a big incentive to move away from horse-drawn streetcars, as the horses required constant care and maintenance, messed up the streets with their manure, and were unable to pull the cars up steep hills. If there was an outbreak of disease among the horses, it meant that the cars had to be pulled by humans.
In 1894, Congress began requiring streetcar companies to switch away from horse power. They had also prohibited overhead wires, so providers had to choose between cables, battery power or underground wire. Some streetcar companies tried cable systems, but it soon became clear that the electric system was superior. At the time this postcard was printed, Washington D.C. had about 100 miles of track within the city and many of the existing streetcar providers had consolidated.
Beginning in 1935, several streetcar lines were converted to bus lines, but as gas rationing during World War II cut down on automobile use, the streetcar service thrived. By 1945, Washington D.C.'s streetcar fleet was the third largest in the United States. Washington D.C. also retained its streetcar system much longer than most American cities. The last streetcar ran in 1962.
Now Washington D.C. is looking at reintroducing streetcar service with 8 lines and 37 miles of track. The district bought its initial streetcar vehicles in conjunction with the City of Portland, Oregon in order to benefit from a bulk purchase. Unfortunately, various construction delays required the cars to be stored for several years in the Czech Republic at large expense. The cars were finally shipped to the U.S. in late 2009. The first two lines, in Anacostia and on H Street, are scheduled to open in 2012. The rest of the system is scheduled to open by about 2020.
One of the problems with transportation planning in Washington is that there are so many competing (or at least conflicting) branches of government with different sets of rules. For instance, the first part of the H Street line falls under the the congressional prohibition of overhead wires, but the rest of it does not.