Joe Biden is many things: a career public servant, a dedicated family man, and now, the 46th President of the United States of America.

He is also a parent, still grieving the loss of his beloved son.

Joseph Robinette "Beau" Biden III was the eldest child from Joe Biden's first marriage. After a distinguished career with Delaware's Army National Guard and two terms as Delaware's attorney general, Beau died of brain cancer in 2015 at the age of 46.

His death devastated the tight-knit Biden family.

Joe Biden embraces his son, Beau Spencer Platt/Getty Images

In an interview with MSNBC's Joe Scarborough earlier this year, Joe Biden tearfully spoke about the loss of Beau.

"Beau should be the one running for President, not me. Every morning I get up, Joe, not a joke, I think to myself is he proud of me?"

"He walks with me," Biden continued. "I know that sounds to some people kind of silly, but he really honest to God does."

In the hours leading up to his presidential inauguration, Joe Biden walked with his son, if only in spirit.

On Tuesday, as Biden prepared to leave Delaware to head to Washington, D.C. for the ceremony, he did so not from the Amtrak station that bears his name, but from the Delaware National Guard Center that bears his son's.

"Excuse the emotion, but when I die, Delaware will be written on my heart. And the hearts of all. We love you all. You've been there for us in the good and the bad. You never walked away. And I am proud, proud, proud, proud to be a son of Delaware," Biden said.

"And I am even more proud to be standing here doing this from the Major Beau Biden facility. Ladies and gentlemen, I only have one regret: He's not here," Biden said tearfully. "Because we should be introducing him as president."

On Inauguration Day, when Biden's surviving children, Hunter and Ashley, entered the inaugural ceremonies with their families, the Marine Corps Band played John Philip Sousa's "The Beau Ideal." The musical tribute meant that all three of Biden's adult children were there, at least in spirit, on the steps of the Capitol.

When President Biden sat down at the Resolute Desk in the Oval Office for the first time, Beau was with him there, too.

A touching photo of Beau is prominently displayed behind the desk so that the President's late son is always watching his father's back.

Beau Biden's photo sits behind President Joe Biden in the Oval Office. Chip Somodevilla/Getty Images

President Biden also shared a tender moment during election night with another young family member. During a live performance from Demi Lovato, Biden held and danced with his grandson, Beau. Hunter Biden's youngest child is eight months old and named after his late uncle.

On arguably the most important day of his life, Joe Biden made sure that Beau was with him every step of the way.

Because that's what you do when you're a parent. You love your children fiercely, even when they're no longer with you.

When our children are not near, we carry them with us.

It doesn't matter how old they get or why they're not there; we carry them with us.

President Biden knows this.

Yesterday, he carried Beau with him all the way to the Oval Office.

Because that's what parents do.