This is a 1960's vintage middleweight bike. It was most probably made by Murray who made most of these designed bikes.

This is an early version of the Sears Spaceliner

In fact, I would be willing to bet that that this bike is either a Hawthorne, Sears OR Montgomery Wards OR JC Penney version.

The rear carrier is unique. I think the real answer probably lies in the chainring and the chainguard. I am leaning toward thinking it is a Hawthorne because of the chubby chainguard.