They didn't fail; it wasn't a problem at the time. Slavery had been such a common practice around the world for so long. Egyptians enslaved Jews centuries ago. Europeans enslaved Native Americans when they first arrived, and when Africans were enslaved in the states, even the African rulers supported this trading.
The colonists opposed the Proclamation of 1763 because it prevented them from settling in the west when most of them already settled in the west. So this mad them mad because that had to move back in to the 13 colonies. That is why the colonists opposed the proclamation of 1763.
Because the rebellion failed.
This question is a broad one and historians cite more than three causes for the US Civil War. Here are some important reasons that this writer believes are especially relevant: A. The founding fathers failed to properly deal with the better goal of ending slavery in a step by step plan, which would have gradually ended slavery either by plans that the British Empire later used or some other formula; B. Slavery had existed in the British colonies since the 17th century and thus had become an accepted "institution"; C. The slave free Northern US States had been complacent over the slavery issue; D. The slavery issue became more complicated when solid Union States were also slave States such as Delaware and Maryland plus even in Washington DC; and E. Statesmen nationwide failed to solve the issues dividing the nation by diplomacy rather than war.
He was rather an optimistic type, who believed that the slavery question could be settled by a local vote in each territory coming up for admission to the USA. He also claimed that a state would automatically be free soil, unless there was active local legislation in favour of slavery. He failed to see that one state voting at a time would bring all the bully-boys descending on that one area. That was what caused 'Bleeding Kansas'.
Even by 1859, most Northerners were not Abolitionists, by any means. The Abolitionists were influential people, and their opinions were widely promoted. But they were not actually very numerous, even after 'Uncle Tom's Cabin' managed to recruit so many new members.
The Crittenden Compromise failed because it outlawed slavery in western states because Abraham Lincoln opposed the western expansion of slavery.
Abraham Lincoln did not believe that he needed to compromise with the South on the issue of expansion of slavery in the Territories. He thought that the Southern States were bluffing and would not leave the Union.
The Crittenden Compromise failed because it outlawed slavery in western states because Abraham Lincoln opposed the western expansion of slavery.
Northerners and Southerners were not ready to resort to violence to abolish slavery
Without a doubt, John Brown's attempt to begin a slave revolt in Virginia was ill conceived. He, for one reason, did not have enough men in his group to carry out any sort of military victory other then taking over the undermanned Federal Arsenal at Harper's Ferry. His force was no larger than perhaps 23 men. And, as they lacked enough weapons, raiding a Federal arsenal quickly received the attention of Federal forces. Aside from that, Brown chose a place near that arsenal that had few slaves. Even then, the few slaves there did not join his forces in a revolt.
the north want to end slavery and the south want to have slavery
All of the above.
Maryland, Delaware, Kentucky, and Missouri.
Kentucky, Missouri, Maryland, Delaware.
He owned slaves, he opposed abolition and he failed to adhere to the terms of the Treaty of Velasco.
It didn't solely - it failed through the overwhelming influx of Eurasian peoples.