Let's take these points one at a time.  

ONE:  

>There are those who propose that Africa didn't become "educated" in free  
>market capitalism until its merchants (African) gained experience in the slave  
>markets with Europeans.  

What does this have to do with the appropriateness of celebrating emancipation.  The practice of slavery IN THE UNITED STATES contradicts free market capitalism.  

For the purposes of assessing the values inherent in celebrating the destruction of slavery in our country, your point here is just irrelevant.

Care to connect, counselor?

*****

TWO:

>"Slavery is opposed to self-government. . . .

>I agree, except the collection and marketing of slaves in Africa could not  
>have taken place without the consent and imprimatur of the "governments" and  
>"political systems" in control of the African cultures at the times of the 
>slave  trade.  

Again--what is the relevance of this claim to the discussion at hand?  If slavery stands in opposition to principles of self-government, and if those principles are ones that are worthy of respect and celebration, then the behaviour of governments in Africa is just not relevant to our purposes here.

*****

THREE:

> It was democracy in the Western cultures, . . . that ultimately killed off the slave trade.

The slave trade is still thriving--the victims are different, and the work they are enslaved to perform is different.  Do not make the error, however, of suggesting that slavery has been permanently ended, in our own country or anywhere else.

The slave trade in Africa died because of changes in the demand, not in the supply.

Emancipation, the event that Juneteenth celebrates, represented Federal government intervention on a massive and violent scale to force the slave states to eliminate slavery.  It represents democracy in action, as you say above.  It was a profoundly desirable thing, and fully worthy of our collective recollection today.

>"Indeed, I will venture to go further.  If you reject the values that  
>Juneteenth celebrates, you are also rejecting the honorable and decent values  for 
>which Ronald Reagan stood. "
> 
>No.  RR was perhaps our greatest American president.   He would not have been 
>very supportive of a "celebration" that resulted in  racial violence.

Ronald Reagan stood for ordered liberty.  That implies responsibility on both the celebrants and the government's parts.  Some of the celebrants were criminal--Reagan would have supported fully the efforts of law enforcement to bring the people responsible for the violence to justice.

You are simply incorrect, however, to suggest that Ronald Reagan did not understand or value emancipation.  The language of abolition figures very powerfully in almost all of his speeches--I will refer you in particular to the speech Reagan gave before the House of Commons in 1982, in which he used the language of anti-slavery to denounce communism.

Reagan knew full well the lessons of American history.  Your notion that he would have no sympathy for the celebration of the core historical principles of his own party is fanciful.
Kevin R. Hardwick, Ph.D.
Department of History
James Madison University