Not so, context matters. One of the drivers for anti child labour laws was to ensure that children were able to attend the free schooling that had been introduced. The driver was not preventing children from working per se, it was making sure they got an education. For example the long school summer holidays were a pragmatic compromise introduced to allow children to work on farms during harvest time. But if free schooling isn't available, or isn't provided up to the same age level, that motivation goes away.
Well, I believe that the best thing is to phase things out rather than go cold turkey. Otherwise you will get a backlash like the civil war that happened here in the USA.
Your command of US history is not so good -- the Emancipation Proclamation was made late in the war. The argument when the war started was about escaped saves; the Northern states were ignoring federal law and asserting state's rights to free them.
Right. The proclamation was made after the civil war started. But the war was because the North started to act as if it no longer agreed with slavery, which the South saw as a threat, since it depended so much on it. Lincoln promised that slavery would not be allowed in new territories, the south states saw the writing on the wall, and that caused the war. Yeah, the United States didn't exactly quit cold turkey before the war but close enough I think.
>>[1] The Civil War started because of uncompromising differences between the free and slave states over the power of the national government to prohibit slavery in the territories that had not yet become states. When Abraham Lincoln won election in 1860 as the first Republican president on a platform pledging to keep slavery out of the territories, seven slave states in the deep South seceded and formed a new nation, the Confederate States of America. <<