Which US president was nicknamed 'Old Rough and Ready'?

Zachary Taylor (November 24, 1784 – July 9, 1850) was the 12th President of the United States, serving from March 1849 until his death in July 1850. Before his presidency, Taylor was a career officer in the United States Army, rising to the rank of major general.

Taylor was commissioned as an officer in the U.S. Army in 1808 and made a name for himself as a captain in the War of 1812. He climbed the ranks establishing military forts along the Mississippi River and entered the Black Hawk War as a colonel in 1832. His success in the Second Seminole War attracted national attention and earned him the nickname "Old Rough and Ready".

His nickname: "Old Rough and Ready" As a military commander, he earned his nickname due to his willingness to sharing the hardships of field duties with his troops, basically not afraid to get his boots dirty alongside his men.