As automakers rebound from the recession, Ford's factory workforce in the United States has grown to become larger than that of General Motors for the first time since at least the 1930s.

Ford has replenished all of the factory jobs it lost during the recession, but GM has only two-thirds as many United Auto Workers members as it had eight years ago, according to an Automotive News report.

A decade ago, GM was ahead of Ford by around 21,000 workers; as of Feb. 1, Ford had 50,703 U.S. hourly workers, while GM had around 50,300.

Ford's numbers have been steadily boosted as the automaker added 10 union jobs on average per day in the last four years. In some cases, the company has been able to insource, or bring supplier jobs in-house.

"We've been able to bring in work that was traditionally done on the outside and do it competitively," said Adrian Price, director of Ford's manufacturing business office, as quoted by Automotive News. "When we put the plans in place four or five years ago, we weren't taking into account all the growth opportunity that we see now."

Ford also manufactures more vehicles in the U.S. than GM, which in turn tops Ford when it comes to production in Canada and Mexico.

FCA US, the automaker known as Chrysler before it merged with Fiat, has been boosting its workforce as well, bringing on 14,000 hourly jobs since it went bankrupt in 2009. It now has around 36,000 workers.

Ford's latest hiring round, which the automaker credited to demand for its newly aluminum F-150 pickup, pushed the automaker past its allowed quota of second-tier employees as outlined by UAW rules.

Since its 2009 bankruptcy restructuring, GM has invested more than $11 billion in U.S. production, according to the automaker.

"It's all market-driven. We build to market demand," said GM spokesman Bill Grotz, as quoted by Automotive News. "The head count hasn't fluctuated that much over the past few years, but we've invested a lot of money in our operations."

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