President Obama extended his "warmest wishes" to families across the U.S. celebrating Kwanzaa, a holiday which honors African-American culture. "Today begins a week-long celebration of African-American heritage and culture through family and community festivities," a statement released the White House on Saturday said. "Kwanzaa's seven principles -- unity, self-determination, collective work and responsibility, cooperative economics, purpose, creativity and faith -- are also shared values that bind us as Americans," he continued. "And in the spirit of the season, we reflect on the blessings of the past year and commit to building a brighter future for all our children. "As families,...