Final answer:
The transition from horse-drawn carriages to cars took several decades, with critical advancements being the electrification of public transportation in the late 19th century and the widespread adoption of automobiles after 1920.
Step-by-step explanation:
The transition from horse-drawn carriages to cars was a gradual process that spanned several decades. The electrification of public transportation and the invention of electric trolleys in the late 19th century were critical steps in reducing reliance on horse-drawn carriages. In 1887, Frank Sprague invented the electric trolley, an improvement over the horse car. Cities like New York introduced electric streetcars in 1881, and others followed suit, with Boston introducing its subway system in 1897.
By 1900, electric streetcars and subways had begun to replace horse-drawn carriages in major cities. However, the most significant shift occurred with the introduction and popularization of the automobile, patented by Karl Benz in 1886, which led to widespread adoption of personal motor vehicles after 1920. The rise of the automobile significantly changed urban layouts and transportation infrastructures, thus marking a definitive end to the horse-drawn carriage era in cities.