The Architectural field has been predominately male-dominated throughout its existence, but there were a few pioneering women that paved the way for others to follow after them.
Louise Blanchard Bethune was the first woman admitted to the architectural professional association (Western Association of Architects, in 1885). She was the first woman admitted to the AIA in 1888 and the first woman member of FAIA in 1889. She is considered by many the first woman to practice architecture in the United States. Her career began when she accepted a position as an apprentice at the office of Richard Waite in the year 1876 in Buffalo, NY.
She opened her own practice in October of 1881. A former colleague from Richard Waite, Robert Bethune, soon joined her, and they were married in December of that year. The firm became known as Bethune & Bethune. "In 1891, William Fuchs, a longtime draftsman with the firm, became the third partner." The portfolio of Bethune, Bethune & Fuchs included everything from small residential to institutional, commercial, and industrial work. Some of the listed buildings that she is known for are 74th Regiment Armory [later Elmwood Music Hall], a number of the Police Stations, Schools, Niagara Storage House, Lafayette Hotel, and more.
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Marion Mahoney Griffin worked in the shadow of Frank Lloyd Wright for several years and later worked beside her husband, Walter Burley Griffin. Marion's mother was a female activist intent on women’s voting rights and educational and labor reform, so it is no surprise that Marion perused an education, and chose a field of study not typical for females. In 1894 Marion became the second woman to graduate from MIT with an architecture degree. She became the first licensed female architect in history. Her Japanese style drawings helped to sell the ideas and became a popular style of presenting architectural design. Her inspiration can be seen in Wright's and Walter Griffin's projects. She recognized the importance of blending architecture and nature, which comes through in the drawings she created and the design overall. She teamed with her husband, Walter Burley Griffin, to win an international design competition for Australia's capital, Canberra. This is known as one of their greatest achievements.
Sources:
Geer- https://archive.curbed.com/2017/6/8/15755858/marion-mahony-walter-burley-griffin-wright-drawings
Norma Merrick Sklareck was the first African American woman to be a licensed architect in the U.S. In 1955 she took a position with the architectural firm of Skidmore, Owings & Merrill. She worked there five years, also serving on the architecture faculty at New York City College. From 1960 to 1980 she was director of architecture at Gruen Associates in Los Angeles. In 1967 she married fellow Gruen architect Rolf Sklarek.
"Norma went on to become vice president of the LA firm Welton Becket Associates, where she spearheaded the design of Terminal One at Los Angeles International Airport. In 1985, she co-founded the firm Siegel Sklarek Diamond with two other women, becoming the first Black woman to co-own an architectural practice. Later in her career, she joined the Jerde Partnership, where she worked on the Mall of America." - 1767designs
Sources:
https://1767designs.com/blogs/news/architect-spotlight-norma-merrick-sklarek
http://architectuul.com/architect/norma-merrick-sklarek