It will help people who are building it to have a job for a while. When it is finished, people will have jobs maintaining it, and when they figure out it didn't help solve the inherent problems, people will have jobs tearing it down again.
So, the answer is yes, the wall will help people have jobs, but looking at who does a lot of construction and building work in the US, these people may not be US citizens.
“It appeared that there had even been demonstrations to thank Big Brother for raising the chocolate ration to twenty grams a week. And only yesterday, he reflected, it had been announced that the ration was to be reduced to twenty grams a week. Was it possible that they could swallow that, after only twenty-four hours? Yes, they swallowed it.”
- George Orwell, ‘1984’
