For the chart below, I used a combination of Decennial Census and American Community Survey data to look at the employment trend for taxi and chauffeur driving between 1860 and 2017 as a percentage of the labor force. Soon after the peak seen in 1930, New York City moved to limit the number of licenses because of perceived oversupply and congestion. With the popularity of ride sharing apps like Uber and Lyft employment is now nearing historic highs.
Analysis: Stata | Visualization: R and Plot.ly