Education Secretary Arne Duncan announced on Friday that he plans to step down in December.

Duncan, who is one of the few original members of President Barack Obama's Cabinet, said he will resign following his seven-year tenure in office.

According to the Los Angeles Times, Duncan will leave a legacy marked by his influence over a wide range of programs from preschool to Ph.D. programs. He also pushed to expand standardized testing and federal financial aid for low-income college students while cracking down on for-profit colleges.

In a memo sent to Department of Education staff, Duncan called his job "greatest honor of my life." He also cited the stress of his commute from work to home as a burden on his family.

"Serving the President in the work of expanding opportunity for students throughout this country has been the greatest honor of my life," Duncan wrote in his resignation note to his staff, according to the L.A. Times.

"Doing so alongside people of the brilliance, ability and moral conviction of the team here at ED has been nothing short of thrilling. We have been lucky to have an a [sic] amazing team here from Day One, but I honestly believe our team today is the strongest it's ever been."

"So it's with real sadness that (I) have come to recognize that being apart from my family has become too much of a strain, and it is time for me to step aside and give a new leader a chance," reads the email.

"Being apart from my family has become too much of a strain, and it is time for me to step aside and give a new leader a chance," Duncan added, reports The Associated Press.

In the interim, President Obama has appointed Deputy Secretary of Education John B. King Jr. to replace Duncan. However, Obama declined to nominate King to be secretary since it would require confirmation by the Senate and likely lead to a showdown between him and the GOP-controlled Senate, reports CNN.

"We do not intend to nominate another candidate," said a White House official speaking on the condition of anonymity.