There nickname was the Yankees.
Yanks, Blue Bellies,
Billy Yank
Lieutenant General Ulysses S. Grant had the nickname of Unconditional Surrender. He was given this nickname as he requested the South to surrender unconditionally and immediately.
Billy Yank was the nickname of the Union solider in the civil war.
Sherman Neckties
The Union Jack is the nickname of the UK flag.
The nickname for the British flag is the Union Jack. Although it is only correctly known as this when flown on a ship.
During WWII the US gave the nickname "The Red Tide" to the Soviet Union.
Yankees
The Union.
It's common nickname is the 'Union Jack'.
The thistle's
Yanks, Blue Bellies,
Billy Yank
Stars and stripes.
Greenbacks.
The "Wobblies" (; Your welcome!