How do you expect someone to answer that when you don't say which nickname you're talking about?
tgtrewtr
The nickname for the southwest US is the "Sunbelt" due to its warm and sunny climate.
"The President's Own" is their nickname.
During WWII the US gave the nickname "The Red Tide" to the Soviet Union.
Empire State
Uncle Sam
The "states", "America."
greenback
I can find no record that any US President had this nickname.
The nickname of the United States is US or USA.
"US" is the nickname for the U.S. The United States is the full name.
uncle Sam