Vice President Joe Biden applauds as US President Barack Obama arrives at the microphone to speak during the dedication of the Martin Luther King Jr. Memorial Oct. 16, 2011 in Washington, DC.

*Nearly half a century after Martin Luther King, Jr. led the historic March on Washington for equality, tens of thousands came to the National Mall in Washington, D.C. for the Martin Luther King, Jr. Memorial Dedication.

The memorial to Dr. King has been open since August, but the dedication was delayed due to Hurricane Irene. As President Obama said, though delayed, “this is a day that would not be denied.”

President Barack Obama reaches out to his family members as they arrive for the dedication of the Martin Luther King, Jr Memorial on the National Mall Oct. 16, 2011 in Washington, DC.

The First Family toured the memorial and then the patriarch spoke at the dedication ceremony in honor of Dr. King’s work to make his dream a reality for all.

Singer Aretha Franklin (R) accepts applause as she finishes her performance with U.S. President Barack Obama, first lady Michelle Obama and Harry Johnson, president and CEO of the MLK National Memorial Project Fund (L) .

(l-r) First Lady Michelle Obama, US President Barack Obama, Vice President Joe Biden, and his wife Jill Biden sing "We Shall Overcome" at the dedication of the Martin Luther King Jr. Memorial Oct. 16, 2011 in Washington, DC.

During his speech, Obama stressed that progress towards Dr. King’s vision has not come easily and there is still more to do to expand opportunity and make our nation more just.

Watch entire speech below.