The best resource to provide evidence to support a written argument about Dr. Martin Luther King Jr.’s achievements would be library books discussing the life of Dr. Martin Luther King Jr.
Library books are typically well-researched, peer-reviewed, and provide in-depth analysis and context about historical figures and events. They often include primary sources, extensive references, and comprehensive discussions of King's accomplishments and impact on civil rights, making them the most reliable source for substantiating an argument.
In contrast, online blogs and television programs may vary greatly in quality and reliability, and an interview with someone who met him may provide personal anecdotes but lacks the broader context necessary for a comprehensive understanding of his achievements.