Thoreau influenced King to write a letter to the Birmingham clergymen expressing his opinion. In the letter he wrote, "You deplore the demonstrations taking place in Birmingham. But your statement, I am sorry to say, fails to express a concern for the conditions that brought about the demonstrations It is unfortunate that demonstrations are taking place in Birmingham, but it is even more unfortunate that the city's white power structure left the Negro community with no alternative."(2) King followed the ideas of Thoreau, put blame on the government, and spoke his mind about unfair segregation laws. In the same way, Howard Zinn addresses many ideas of a citizens voice being heard. He wrote, "Until the 1960's, we saw the national government acquiescing in racial segregation, indeed in the violation of the Fourteenth and Fifteenth Amendments to the Constitution. Only when black people in the South pushed themselves into view, brought public attention by acts of civil disobedience, did the government finally respond."(20) Thoreau influenced those African Americans to speak their minds about the unjust laws, gaining the governments attention.
Thoreau had the idea that a governing body should not control its people and that it is the right of the citizens to alter and defy the government. Thoreau expressed his opposition to the government when he said, "Unjust laws exist: shall we be content to obey them, or shall we endeavor to amend them, and obey them until we have succeeded, or shall we transgress them at once?"(320) Thoreau addresses the idea of defying the government when the law is unjust. Additionally, Howard Zinn said, "I began to talk about Henry David Thoreau and his decision to break the law in protest against the U.S. invasion of Mexico in1846."(4) Later, Thoreau's defiance would influence Martin Luther King to also defy the government.