Joe Biden will be sworn in as the 46th President of the United States, while Kamala Harris will take oath as the first woman Vice President on Wednesday, in the midst of growing concerns over the safety of the historic inauguration following the recent violent attack on the Capitol Hill by pro-Trump supporters.
Chief Justice John Roberts will administer the oath of office to Biden just after the clock strikes 12 (local time) at the West Front of the Capitol -- the traditional location -- under the unprecedented security umbrella of more than 25,000 National Guards, who have transformed the capital into a garrison city, mainly because of the threat of violent protest by Trump's supporters.
Biden, 78, will take the oath on his 127-year-old family Bible, which will be held by his wife, Jill Biden.
Biden, who will be the oldest President in American history, will deliver his first presidential address to the country after taking oath shortly after noon.
The historic speech, with the theme of unity and healing, is being prepared by his Indian-American speech writer Vinay Reddy.
Harris, 56, will make history as the first female, first Black and first South Asian American vice president when she will be sworn in by Justice Sonia Sotomayor, the first Latina member of the Supreme Court.
Sotomayor administered the oath to Biden as vice president in 2013.
She will be sworn in on two Bibles -- one that belonged to a close family friend named Regina Shelton and another that belonged to Thurgood Marshall -- the country's first African American Supreme Court justice.
This year, however, the transition stands out for its acrimony.
The process usually starts straight after the election, but it started weeks late after President Donald Trump refused to accept the result of the November 3 election won by Biden, a Democrat.
Trump has said he will not attend the inauguration. Trump, a Republican, will vacate the White House hours before the inauguration and is expected to travel to his Mar-a-Lago club in Florida.
The scaled down inauguration is expected to begin around 11 am with an invocation by Leo Jeremiah O'Donovan, a Jesuit priest who is a close friend of the Biden family.
Andrea Hall, the first African American female firefighter to become captain of the Fire Rescue Department in South Fulton, Georgia, will recite the Pledge of Allegiance.
Singer-dancer Lady Gaga will sing the national anthem and Amanda Gorman, who became the country's first Youth Poet Laureate in 2017, will read a poem she has written for the occasion called 'The Hill We Climb'.
She would be followed by a performance by actress-singer Jennifer Lopez.
Silvester Beaman, pastor of Bethel African Methodist Episcopal Church in Wilmington, Delaware, will deliver a benediction.
After the swearing-in ceremony, Biden and Harris will attend a traditional Pass in Review with members of the military on the East Front of the Capitol, signifying the peaceful transfer of power to a new commander-in-chief.
Biden, Harris and their spouses will visit Arlington National Cemetery in Virginia, where they will lay a wreath at the Tomb of the Unknown Soldier.
After the wreath ceremony, they will head to the White House, where they will get a presidential escort.
That will kick off the virtual 'Parade Across America', featuring performances from all 56 states and territories.
Traditionally, when the new president arrives at the Oval Office and occupies the chair in front of the resolute desk, a letter from his predecessor awaits him.
Given the circumstances that Trump is leaving, speculation is rife that there might not be any letter at all. Trump not only refused to concede the elections for more than two months, but also did not invite his successor to the White House as is the custom here.
At night, Biden is forgoing the traditional inaugural balls because of the COVID pandemic, and he will instead take part in a television event called 'Celebrating America'.
Biden enters the White House with the top challenge to lift the country from the devastation of a raging pandemic that has killed more than 400,000 Americans and thrown millions into economic distress.
Revival of the economy, which has been badly bruised by the pandemic, is another challenge that he faces.
Meanwhile, the American capital has been virtually turned into a garrison city, amidst multiple reports of threats and more armed violence by pro-Trump supporters to disrupt the events.
The area in and around Capitol Hill, a large part of Pennsylvania Avenue and the White House has been made out of bounds for the general public with eight-feet high iron barricades being erected.
The entire city is on high-alert as authorities are receiving multiple reports of violent threats from various groups at the level of the incident that happened on January 6 -- when hundreds of supporters of Trump stormed Capitol Hill.
At least five people, including a police officer, died in the incident.
In addition to converting downtown Washington, DC into a fortress, security in and around 50 State Capitols has also been put on high alert to ensure a peaceful transition of power.
The Federal Bureau of Investigation in its internal bulletins has warned of the potential for violence in Washington, DC and at all 50 state Capitols.
US defence officials say they are also worried about an insider attack or other threat from service members involved in securing Biden's inauguration, prompting the FBI to vet all of the 25,000 National Guard troops deployed for the event.