How effective were the 13th, 14th, and 15th Amendments?

The 13th Amendment was very effective.  The other two were not very effective at all, at least not for about 90 years after they were ratified.

The 13th Amendment abolished slavery.  Since there was little opposition to this and since it was easy to enforce, it was very effective.  Slavery was effectively ended by the Civil War and by that amendment.

The 14th Amendment gave blacks equal rights and the 15th guaranteed them the right to vote.  These amendments were hardly adhered to in any way.  "Jim Crow" laws circumvented the 14th Amendment while things like literacy tests, poll taxes, and the "white primary" prevented blacks from voting.  It was not until the Civil Rights Movement that these amendments became effective in any real way.

What is the importance of the 13th, 14th, and 15th Amendments?

The Thirteenth, Fourteenth, and Fifteenth Amendments are often known as the "Civil War Amendments" or the "Reconstruction Amendments" because they were passed in the aftermath of the war and amidst the political ferment of Reconstruction. Each was concerned with protecting the basic rights of African-Americans newly liberated from slavery by the war. The Thirteenth Amendment outlawed slavery permanently, the Fourteenth Amendment extended citizenship and "equal protection" under law to all citizens (a term it also defined), and the Fifteenth Amendment protected, or attempted to protect, the right to vote for African-American men. Even as these amendments were being passed, their provisions--especially the Fourteenth and Fifteenth Amendments--were being challenged by white Southerners, and while there was a window where black men enjoyed their protections, this period quickly waned with the end of Reconstruction and the establishment of Jim Crow. 

In the long term, the Fourteenth Amendment in particular has taken on added significance for several reasons. One is that the Supreme Court has used it to overturn unequal laws--most famously in Brown v. Board of Education. The Court has also used its guarantee of equal protection and equal "provisions and immunities" to expand the provisions of many of the other amendments to the states. This basically meant that states, like Congress, cannot pass laws that violate amendments like the First, the Second, the Fourth, and so on. The definition of citizenship in the Fourteenth Amendment has also proven significant in that it formally establishes citizenship by birth, which guarantees citizenship to the children of immigrants. The Fourteenth has thus proven to have the most lasting--and the broadest--significance, though the Fifteenth has also been invoked to overturn discriminatory voting laws.

How effective were the 13th, 14th, and 15th amendments and when did they become effective?

The Thirteenth Amendment, because it was passed immediately in the wake of the Civil War, had almost immediate effect in the sense that it banned chattel slavery. However, as Reconstruction collapsed, African-Americans and many poor whites were often driven by necessity and by a white-controlled economy into arrangements that often resembled slavery. Many sharecropper contracts, in addition to establishing onerous economic terms, also gave property owners the ability to confiscate property and even, in some cases, physically punish sharecroppers. So the letter of the   Thirteenth Amendment had immediate effect, while its spirit was violated as a matter of course in the South.

It was precisely the existence of "vestiges of slavery," including these contracts and the emergence of so-called "Black Codes" that brought about the Fourteenth Amendment. It was designed to guarantee equal protection under law to all American citizens, which under its definition, included virtually all living slaves. But extremely limited readings of the Fourteenth Amendment by the Supreme Court in a series of decisions in the late nineteenth century opened a legal space for states to deny the protections of the amendment to African Americans. The "separate but equal" doctrine outlined in Plessy v. Ferguson (1896) gave legal sanction to racial discrimination by state governments.

The Fifteenth Amendment was an acknowledgement of the reality that African-Americans could never achieve legal equality in the South without political power. It thus extended the franchise to all men regardless of race or condition of prior servitude. Yet, as is well known, southern governments found loopholes to avoid granting the franchise, and after Reconstruction collapsed in 1876, blacks were denied the vote both through legal devices such as poll taxes, literacy tests, and even selective gerrymandering, and through the use of terror and other repressive measures. The full benefits of the Fifteenth Amendment were not realized until the Voting Rights Act of 1965, the result of a long civil rights struggle. 

What have been the effects of the 13th through 15th Amendments?

There have been two major effects of these amendments.

First of all, all three of the amendments taken together have been used to advance the cause of minority rights in the United States.  This is especially true of the 14th Amendment.  This amendment says that all people shall enjoy the equal protection of the laws.  This clause has been the basis for much of the movement towards equal rights for blacks, women, gay people, etc.  The 15th Amendment has been used to protect the voting rights of minorities from being diluted either explicitly or through more circuitous means.

Second, the 14th Amendment has been used to incorporate the Bill of Rights, making it apply to the states as well as to the federal government.  Until the early 1900s, the Bill of Rights did not apply to state governments.  Over time, the Supreme Court has used the 14th Amendment to require states to abide by the Bill of Rights as well.

What are the 13th and 15th amendments?

The thirteenth amendment did indeed end slavery; but it bears no relationship to the Emancipation Proclamation, nor was it a requirement for Southern states to return to the Union, as it was generally accepted that the Southern states had never left the union. It is more correct to state that, because they had engaged in rebellion, Congress would not seat the senators and representatives from those states until the amendments were ratified, including the 14th. It was necessary because slavery was constitutionally protected, and there was no other way to be rid of it. The Emancipation Proclamation was a wartime measure which had no effect whatsoever other than to give the North the moral high ground in the war.

The 15th Amendment guaranteed the right to vote to all citizens, and was specifically intended to guarantee black men the right to vote. Obviously, some Southern states went to great lengths to prevent the vote; but the intent of the amendment was clear.