WASHINGTON, DC (AP).- Construction is finally under way on the Martin Luther King Jr. Memorial on the National Mall after more than a dozen years of planning, fundraising and legal wrangling. Workers have been clearing the site on the Tidal Basin since Dec. 28. They will move some trees to another part of the mall, including a few of Washington’s famous cherry trees. By February, heavy construction will begin. Monday will mark the first King holiday, though, when organizers can finally see their work in progress. “Everyone in the office is taking a deep breath,” executive architect Ed Jackson Jr. said in an interview Friday. “Although it’s been a labor of love, it’s been a long road, 13 years for me.” It was supposed to be completed by now. President Bill Clinton signed a law authorizing the memorial in 1996, and President George W. Bush appeared at a ceremonial groundbreaking with Oprah Winfrey and others in 2006. Numerous design approvals and a disagreement with the National P