Goins' Encyclopedia of Cutlery Markings lists 21 instances of companies using the "Union" marking in some way. Based on your razor, I believe it's one of these four (which appear to be the same company). I will list exactly what's written in this book:

Union Knife Works (curved) c.1911-1913
Union Knife Works New York (curved) c.1911-1913
Union (curved) (line) Knife Works NYC c. 1911-1913
Union Knife Works New York USA c. 1911-1913 Located on Main Street, in the village of Union, New York. This company was in existence for only a few years. It is unknown when they were founded, the 1911 date is the first city directory listing.

There is one more that may apply, but I listed the definite New York first, as the most probable. The other possibility is as follows:
Union Manufacturing Company (curved) c. 1860-1953 A trademark used by Kayser, Ellison & Company.

The box probably isn't original to the razor.