Please answer a question about the following article about Atlantic City, New Jersey:

Like many older east coast cities after World War II, Atlantic City became plagued with poverty, crime, corruption, and general economic decline in the mid-to-late 20th century. The neighborhood known as the "Inlet" became particularly impoverished. The reasons for the resort's decline were multi-layered. First of all, the automobile became more readily available to many Americans after the war. Atlantic City had initially relied upon visitors coming by train and staying for a couple of weeks. The car allowed them to come and go as they pleased, and many people would spend only a few days, rather than weeks. Also, the advent of suburbia played a huge role. With many families moving to their own private houses, luxuries such as home air conditioning and swimming pools diminished their interest in flocking to the luxury beach resorts during the hot summer. But perhaps the biggest factor in the decline in Atlantic City's popularity came from cheap, fast jet service to other premier resorts, such as Miami Beach and the Bahamas.

After the war, what form of transportation became more readily available to many Americans?
automobile