Brunelli subsequently attended Colorado College for two years, before he received an appointment to the United States Naval Academy at Annapolis, Maryland.

[1][2][3] Many of his classmates had distinguished careers and became general officers: John S. McCain Jr., Horacio Rivero Jr., Charles T. Booth, Lawson P. Ramage, Bernard F. Roeder, Frederick L. Wieseman, Frederick J. Becton, Charles B. Brooks Jr., Ernest B. Ellsworth, Wilmer E. Gallaher, Andrew J. Hill Jr., Harlan T. Johnson, Frederic S. Keeler, Edward J. O'Neill, Forsyth Massey, Berton A. Robbins, Jr., Kinlock C. Walpole, Nelson K. Brown, Edward J. Dillon, Robert E. Fojt, Edward H. Forney, Bankson T. Holcomb Jr., Lewis C. Hudson, Clifford H. Shuey or Samuel G.

Brunelli was transferred to the Marine detachment aboard the aircraft carrier USS Lexington in March 1934 and spent next sixteen months on patrol duties along the West Coast.

[1][2] In June 1934, Brunelli was promoted to the rank of first lieutenant and one year later w was transferred to San Diego, California, where he was attached to the 2nd Battalion, 6th Marine Regiment stationed there.

[1] However, he dropped out of training in December 1936 and was transferred back to the infantry and appointed adjutant and assistant operations officer on the staff 1st Marine Brigade under Brigadier General James J. Meade.

Brunelli exchanged this administrative assignment with sea duties aboard the heavy cruiser USS New Orleans, where he served with the rank of captain as commanding officer of the Marine detachment from June 1938.

[1] He was subsequently transferred to Camp Pendleton, California, where he succeeded Lieutenant Colonel Homer Litzenberg as commanding officer of 3rd Battalion, 24th Marines.

His unit was later attached to the 4th Marine Division under Major General Harry Schmidt and finally sailed to the Pacific theater in January 1944.

[1] During the upcoming Battle of Kwajalein at the beginning of February 1944, Brunelli was appointed commander of an Assault Landing Team (consisting of his battalion) in the capture of Namur Island.

He reestablished his lines, resumed contact with the adjacent units and launched a successful attack which eliminated Japanese positions in the area.

He personally made a reconnaissance of his entire front line and then reorganized his badly depleted units into two rifle companies and resumed the attack until all enemy resistance was defeated.

Brunelli remained in Quantico until June 1950, when he was promoted to the rank of colonel and transferred to the staff of Commander, Amphibious Force, Pacific Fleet at Coronado, California.

Brunelli remained in this post until the end of July 1955, when he was transferred to Washington, D.C., and appointed to the office of Joint Chiefs of Staff under General Omar Bradley.