As one of TIME’s White House photographers for nearly two decades, Diana Walker says her primary goal with politicians was to “show you how human they were.” This was never clearer than during her time with Hillary Clinton, whom Walker captured throughout her historic transformation from First Lady to U.S. Senator to Secretary of State.

True to her aim, Walker’s pictures help convey the person behind the politician. Whether on the trail in New York or on a military plane, her images offer a rare window into a person familiar to most, yet known to few. “I was just shooting I saw,” Walker says. “And that’s who I saw.”

One of Walker’s images even went viral. As the photographer was with the Secretary on a plane bound for Libya, Clinton put on her sunglasses and grabbed her phone. The image became the meme “Texts from Hillary.” In this video, Walker recounts how she captured the now-iconic frame.

Diana Walker is a regular contributor to TIME and worked as TIME’s White House photographer for nearly two decades. You can see more work in her latest book Hillary

Sign up for Inside TIME. Be the first to see the new cover of TIME and get our most compelling stories delivered straight to your inbox. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.