A cornerstone of Donald Trump's presidential campaign was a vow to bring back US manufacturing by pressuring firms to stay in the country. Since his inauguration, President Trump has made numerous announcements about companies pledging to build factories in the US, however those promises are often broken. 

In 2013, Foxconn, the manufacturer of iPhones and other electronic devices, announced it would invest 30 million dollars in a new factory and hire 500 workers near Harrisburg, Pennsylvania. At the time, Bub Manning was Principal at Quandel-a construction company servicing that part of the country. But four years later, there's no new Foxconn plant in Harrisburg. 

“I don't know why it was never built. It almost sounds like it was a premature announcement of something that might happen,” David Black, head of the Harrisburg Chamber of Commerce, said.

“Foxconn is going to spend a tremendous amount of money on building a massive plant and probably more than one,” Trump announced in January.

With the announcement, Foxconn pledged to invest seven billion dollars on a plant that would hire up to 50,000 US workers. Trump later announced that Intel would also invest in a new plant. But like Foxconn, Intel has a history of breaking promises. In January, Foxconn's CEO distanced himself from his earlier pledge to invest in US, saying it was a wish, not a promise. Those in Harrisburg say they now take big announcements by politicians and CEO's with a grain of salt. 

Trump won the state of Pennsylvania in part because he promised to bring back manufacturing jobs. But experts say even if companies set up shop in cities like these, it won't necessarily translate into lots of jobs. That's because robots will likely be doing most of the work.