Women have been fighting and sacrificing for this country much longer than you may think -- one even going as far as disguising herself as a man to serve.

In September 2017, a Marine officer passed the rigorous requirements to become the very first female infantry officer. In addition, two officers made history by becoming the first women to graduate from the traditionally all-male U.S. Army Ranger School.

Women have blazed a trail of innovation and made military history. Here are some pioneering women who forever changed the modern military landscape:

On July 11, 1919, the American Legion granted a charter to the first post of women's Marine Corps reservists.

Known as Belleau Wood Post No. 1, its membership consisted of 90 women who had worked at Headquarters Marine Corps. Johnson was a charter member of this post.At the end of World War I, the Marine Corps, like all services, began the steady disenrollment of women, including Johnson, from active service. After her brief military career, she became a clerk in the War Department.

Known as "Amazing Grace," Commodore Hopper's importance in U.S. naval history is apparent everywhere you turn: a destroyer was named after her (USS Hopper, DDG-70), as was the Cray XE6 "Hopper" supercomputer.

As founder of the COBOL programming language, a precursor to many of the software code approaches of today, her work is legendary among computer scientists and mathematicians.In 1943, during World War II, she joined the United States Naval Reserves. She was assigned to the Bureau of Ordinance Computation Project. There, she became the third programmer of the world's first large-scale computer, called the Mark I.

In 1983, a bill was introduced by Rep. Philip Crane (D-Ill.) who said, "It is time the Navy recognized the outstanding contributions made by this officer recalled from retirement over a decade and a half ago and promote her to the rank of Commodore.

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The bill was approved by the House, and at the age of 76, she was promoted to commodore by special presidential appointment. Her rank was elevated to rear admiral in November 1985, making her one of few female admirals in the history of the United States Navy.By the time of her death in 1992, Hopper was renowned as a mentor and a giant in her field, with honoree doctorates from more than 30 universities. She was laid to rest with full military honors in Arlington National Cemetery.

Iskra served in the Navy 21 years and was the first female to command a U.

S. Navy ship. Iskra retired from the Navy in 2000 and earned her Ph.D. in sociology from the University of Maryland.

She is the author of "Breaking Through the Brass Ceiling: Elite Military Women's Strategies for Success" and "Women in the United States Armed Forces: A Guide to the Issues." The story of her first command is below:

"I hadn't realized what a big deal being the first woman to command a ship would be until I arrived in Naples, and on my desk was a stack of congratulatory cards and letters from people I didn't even know!" she said. "I also got a few cards from people I hadn't heard from in literally decades!"Soon afterwards, the public affairs officer from Naples asked to do an interview.

That was the one that was published soon after I took command, to news outlets all over the world, even in Saudi Arabia, which freaked my husband out, as even back then, we were worried about terrorism."About three weeks after I took command, Desert Storm started in the Gulf and we were ordered underway towards the Suez Canal to intervene in case the Canal was mined or otherwise blocked. We picked up an [Explosive Ordnance Disposal] team in La Maddalena, Sardinia, and headed to an area on the Mediterranean side of the canal, where we stayed for the entire duration of the war. No mines were laid, though we did have several interesting incidents, but those are stories for another day."

Lt. Col. Martha McSally

Iraq War

McSally was the first American woman to fly in combat after the 1991 lifting of the prohibition of women in combat. She flew the Fairchild Republic A-10 Thunderbolt II 'Warthog' close air support aircraft over Iraq and Kuwait during Operation Southern Watch. She is also the first woman to command a USAF fighter squadron, the 354th Fighter Squadron (354 FS) based at Davis-Monthan Air Force Base, Arizona.

In 2002, during her tenure as a pilot, she also was embroiled in a controversial lawsuit requiring all female military personnel to wear the Muslim abaya, a black head-to-toe robe worn in certain Muslim cultures and perceived as a sign of subordination to men.

She won the case against Secretary of Defense Donald Rumsfeld and the U.S. Department of Defense, on the grounds that the military's dress policy violates McSally's constitutional rights to equal protection and the freedoms of religion and speech.

McSally, now a Republican congresswoman, quickly points out that the oath for a military officer -- to support and defend the Constitution against all enemies, foreign and domestic -- is the same for a member of Congress."I served my country in uniform for 26 years," the 46-year-old said in an interview. "I personally consider this just a continuation of my service to my country.

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Sgt. Leigh Ann Hester

Iraq War

Hester, of the 617th Military Police Company, a National Guard unit out of Richmond, Kentucky, is the first woman to receive the Silver Star since World War II for exceptional valor. Hester's squad was shadowing a supply convoy on March 20, 2005, when anti-Iraqi fighters ambushed the convoy. The squad moved to the side of the road, flanking the insurgents and cutting off their escape route.