Short answers, pulled from the story.
Approximately 3,500 Hispanics joined the war at its outset, a figure that grew to around 10,000 by the war's end. About 2,500 served the Confederacy and 1,000 initially joined the Union. The largest groups were Mexican-Americans, Puerto Ricans, and Cubans.
Admiral David Farragut was the highest-ranking Hispanic in the war, becoming the first person in United States Navy history to hold the rank of full admiral, a promotion he received on the 25th of July 1866. He was the son of Spanish-born Jordi Farragut.
When the USS Tecumseh struck a mine and sank, Farragut shouted through a trumpet to the fleet and received the reply "Torpedoes!" He then issued the order "Damn the torpedoes! Full speed ahead!" The battle on the 5th of August 1864 secured Mobile Bay for the Union.
Two notable Hispanic women served the Confederacy: Lola Sanchez, born in 1844 in Armstrong, Florida, of Cuban descent, worked as a spy after Union forces imprisoned her father; and Loreta Janeta Velazquez, a Cuban woman who disguised herself as a male soldier under the alias Lieutenant Harry Buford, fought at Bull Run, Ball's Bluff, Fort Donelson, and Shiloh, and later became a spy.
Three Hispanics received the Medal of Honor. Corporal Joseph H. De Castro of the 19th Massachusetts Infantry was the first Hispanic-American recipient, for seizing a Confederate flag in battle. Seaman Philip Bazaar was honored for carrying dispatches under fire at Fort Fisher on the 12th of January 1865. Seaman John Ortega was the first Hispanic member of the United States Navy to receive the medal, for his role in coastal raids in South Carolina in 1864.
Both brothers were appointed United States consuls in Cuba after the war, but resigned to join Cuba's Ten Years' War against Spanish rule in 1868. Federico Fernandez Cavada was captured, tried, and executed by firing squad in July 1871. His brother Adolfo was killed in battle on the 18th of December 1871 at the coffee estate La Adelaida near Santiago de Cuba.