Compare and contrast King’s “Letter From Birmingham Jail” and Obama’s “A More Perfect Union.”

The greatest contrast between King's "Letter from a Birmingham Jail" and President Obama's "More Perfect Union" speech is the context. As the title suggests, King wrote his letter while in jail during the 1963 campaign against segregation in Birmingham. Obama, on the other hand, delivered the "More Perfect Union" speech in Philadelphia while running for President in the spring of 2008. There are also significant differences in message and purpose. Then-Senator Obama was speaking under pressure to distance himself from remarks made by his former minister, Jeremiah Wright. As such, he emphasized his own multi-racial past, and, while refusing to disown Wright, undertook a conciliatory tone. King, on the other hand, was strident in his disagreement against liberal ministers who refused to support his direct action tactics in Birmingham. While both men make specific appeals to American history to buttress their arguments about freedom and liberty for all, King's letter is a challenge to all of those who argued that the movement for civil rights was progressing too quickly. Obama also pointed out the problems confronted by African American communities (though he compared these issues with those faced by working-class white families), calling on African Americans to continue to seek, along with whites, "a full measure of justice." So these two documents each draw on American ideals, and for similar reasons. But they are very different in tone, a result of the very different contexts in which they were written.
https://www.africa.upenn.edu/Articles_Gen/Letter_Birmingham.html

https://www.nytimes.com/2008/03/18/us/politics/18text-obama.html