Army Secretary Mark Esper was named the new acting secretary of defense by President Trump on Tuesday after Patrick Shanahan withdrew his nomination.

Esper, 56, has acted as the 23rd Secretary of the United States Army since Nov. 17, 2017. His duties included the recruitment, organization, training, equipping and care of 1.4 million active duty, National Guard, Reserve Soldiers, Department of the Army Civilians and their families, according to his Pentagon biography.

TRUMP PUTS ARMY SECRETARY IN CHARGE OF PENTAGON AS SHANAHAN DROPS OUT OF CONTENTION FOR SECDEF

Before becoming Army secretary, he held executive positions at Raytheon Company, a defense contractor. He was most recently the vice president for government relations.

He has a history of military service

Esper graduated from the United States Military Academy in 1986 — the same year as Secretary of State Mike Pompeo. He received his commission in the infantry and completed Ranger and Pathfinder training.

Esper served on active duty for over a decade. In the early 90s, he served with the 101st Airborne Division in the Gulf War. He later commanded an airborne rifle company in Europe.

Esper was serving as Army secretary when President Trump announced him as acting secretary of defense. (AP)

Following his service on active duty, he served in both the Virginia and District of Columbia National Guard and Army Reserve. He retired in 2007.

He has held several positions in Washington

His experience extends to Capitol Hill, where he has held several posts. He previously served Senate Majority Leader Bill Frist as a national security advisor and Senator Chuck Hagel as his legislative director and senior policy advisor.

He was also responsible for national security issues as a professional staff member on the Senate Foreign Relations and Government Affairs committees.

At the Pentagon, he served on the Army staff as a war planner before becoming the Deputy Assistant Secretary of Defense (Negotiations Policy) in the Office of the Secretary of Defense.

CLICK HERE TO GET THE FOX NEWS APP

He has earned prestigious awards

His military awards and honors include the Legion of Merit and Bronze Star Medal, the Kuwait Liberation Medal and Kuwait Liberation Medal — Saudi Arabia and the Combat Infantryman Badge. He also received the Department of Defense Medal for Distinguished Public Service.

Fox News' Lucas Tomlinson contributed to this report.