Working moms, we salute you.

And photographer Tara Ruby [1] does it quite literally as part of a portrait series in which she documents women in uniform nursing their children. The inspiration for the collection came after she shot a now-viral image of 10 active-duty military moms [2] breastfeeding their infant babies.

Since that fateful shot, she's expanded her reach outside of the armed forces — but has found her subjects no less awe-inspiring. From a firefighter in head-to-toe tactical gear [3] to a teacher in a blazer to a nurse in hospital scrubs, she hopes to document the mother who has to, day in and day out, put on a uniform, leave her family to go to work, and then come home to breastfeed her baby before bed. In fact, her message — thanks to the powerful inclusion of a Las Vegas showgirl — is that when it comes to that daily grind, every mom is a hero for doing it.

Her latest image, however, returns to her series' roots: in honor of the fifteenth anniversary of the 9/11 attacks, she released what might be the first documented image of a US Marine breastfeeding her infant in uniform.

Read on to find out more about the women Ruby has included in her series so far.

Airman

"An active-duty mom tandem-nurses her two little boys."

Labor and Delivery Nurse

"Her mommy is an L&D nurse and still breastfeeds! I love watching the older babies. Apparently putting toes in mommy's mouth becomes part of the routine!"

Doctor

"This mommy is a doctor and has successfully breastfed for six months with no end in sight."

Las Vegas Showgirl

"This momma dressed her little guy up like the great Elvis, and nursed him on the street for me. We might have drawn a crowd, and they gave her such words of support."

Teacher

"A teacher nurses her little girl while sitting on the floor of a local library. Her uniform is one made for working with happy and smiling first graders."

Nurse

"This beautiful momma is nursing her last baby. She's a full-time working nurse."

Firefighter

"This was made to show the power of a working mother, for all mothers that might be in the firefighting career field."

Marine

"Today, as we focus again on our nation I was inspired by this momma. We are a strong nation because of strong mothers!"