Quadricycle - What it may have looked like.
Model T production began in 1908 and went through 1927. Almost 15 million Tin Lizzie's were built during this time period.
The secret behind the success and mass production was the assembly line. Ford used the concepts of interchangeable parts and specialization to make this happen.
The reason the Model T was so popular among the citizens was due to the extremely affordable price. In 1916 the price dropped to $360 and by 1918 half of the cars in America were Model Ts.
This success remained throughout the 1920s for Ford until the end of the Model Ts production in 1927. With so many Americans owning cars now, the construction of roads and highways took off.