President Obama and first lady Michelle Obama extended Kwanzaa greetings on Friday, the first day of the weeklong celebration.

"Today begins a celebration highlighting the rich African American heritage and culture through the seven principles of Kwanzaa—unity, self-determination, collective work and responsibility, cooperative economics, purpose, creativity and faith,During this season, families come together to reflect on blessings of the past year and look forward to the promises in the year ahead,"As we remain committed to building a country that provides opportunity for all, this time of year reminds us that there is much to be thankful for,"