This is the World War I draft registration for Albert Rosenthal, who was Harold's father.
Here's a copy of the (modern) transcription copied from ancestry.ca
U.S., World War I Draft Registration Cards, 1917-1918
Name: Albert Rosenthal
City: St Paul
Birth Date: 15 Aug 1890
Draft Board: 04
Here are my notes about this document:
In the section about his dependents it says "wife and son 3 yrs". (This fits with Harold's date of birth being in Dec. 1913.)
His home address is 358 Smith Ave., Saint Paul (see this address today in Google Maps), and his work address is So 79 Robert St., Saint Paul (see this address today in Google Maps). It doesn't specify whether this is Smith Ave. North or South, but Harry Rosenthal's draft registration, with the same address, says "North" so it must be North. Also, the "So" preceding the word "Robert" is difficult to read -- it could be "S."?
For "By whom employed" he says "Self" and gives the name of the company, Sanitary Bottling Works.
He gives his birthday as Aug. 15, 1890. (The dates he gave in his naturalization papers are July 30, 1890 and Sept. 15, 1890; presumably he didn't know his exact date of birth.)
For the question about whether he is naturalized he says "1st Papers" which is a commonly used expression to indicate one has submitted a declaration of intention (which in fact he had done in 1909).