To answer your first question, there were 13 colonies which later became the original States of the United States (out of some 21 British colonies in North America) and the people who migrated to the 13 colonies were significantly different from colony to colony.

Some of the colonies were founded by deeply religious people who wanted more freedom to follow their faith than they perceived in Britain. These were essentially Massachusetts (Puritans and Pilgrims), Pennsylvania (Quakers) and Maryland (Catholics). The other New England colonies were influenced by the Puritans, (sometimes - as in Rhode Island - by opposition to the Puritans).

New York, New Jersey, Delaware, were all conquered by the British. Their original colonists were Dutch (or Swedish and then Dutch in the case of Delaware) but these founder populations were overtaken by mostly British colonists of no particular religious fervor after becoming British.

The Southern Colonies of Virginia, North and South Carolina, were settled by people with no particular religious grievances (they were mostly Anglicans or Presbyterian Scots) who emigrated to make better lives for themselves. The original settlers in Georgia were criminals, as it was a penal colony.

As you can see, the people who mainly migrated from Europe to what would become the USA were a pretty diverse bunch. Some were deeply religious, looking for more religious freedom, some were not. Most were from Britain, but many were from the Netherlands, France (Huguenots), a small number from Sweden, some small number from many other places in Europe (as well, of course, as many from Africa as slaves, not from their own free will).

It is extraordinary that the diverse populations and cultures in these 13 colonies managed to all become irritated enough by the British to engage in Revolution, and all managed to eventually unite into a single country.

I'm going to answer the second question.

The North wasn't a monolithic entity where everyone had exactly the same opinion on everything. There were the abolitionists in the North, who were against slavery for various reasons. Some feared slavery spreading west and that they would have to compete for jobs with black slaves who would, of course, be working for free. Some were against slavery for moral reasons, but that didn't necessarily mean they believed in racial equality. Quite a lot of abolitionists thought that black people were inferior, but that that didn't make it okay to enslave them. And, of course, not everyone in the North was an abolitionist, although the North was at least enough against slavery to have abolished it throughout the North.

Abraham Lincoln was personally against slavery and had spoken out against it prior to the war. However, at the start of the war, Lincoln considered the preservation of the Union to be the most important issue. He said, "if I could save the Union without freeing any slave I would do it". Nevertheless, given his prior opposition to slavery, his Emancipation Proclamation was probably motivated by a mix of moral and military concerns. Beyond Lincoln himself, there were more radical members of his party who were more decisively against slavery, such as Thaddeus Stevens, and did all they could against it.

I will try to answer both questions here:

1. You are partially correct. The first attempt at colonization in America was at Roanoke Island. This attempt failed, but it was not founded by religious exiles, Queen Elizabeth founded it in order to compete with Spain’s vast North American colonies. King James chartered Jamestown, for the Virginia Company. The Virginia Company was a Joint-Stock company, run by private investors in England who wanted the colony to become profitable by finding gold or silver as the Spanish had. The third attempt, the famous Plymouth Colony, was chartered for the Puritans (the “deeply religious” people you were referring to). The Puritans felt oppressed by the Church of England, and the Church didn’t want them around, so the Puritans were given a charter to colonize certain land in the New World.

2. Before the Civil War, the North was split on its view of slavery. Some people were abolitionists, meaning they were against slavery, but some northerners were not opposed to slavery. These people were mainly merchants, whose livelihood depended on shipping the slave-harvested southern cotton. It is important to note that despite being against or neutral regarding slavery, the north had racist tendencies. Immigrants viewed unskilled black laborers as job competition, and as such, immigrants preferred a culture that would give them a better shot at having jobs. Early in the war, confederate victories led Britain to lend a degree of support to the Confederates (i.e. trading cotton for guns, swords, ammunition, as well as building ships to create a Confederate Navy). A British backed Confederate States of America was much more of a threat than the CSA without British support. After the Battle of Antietam, the first major Union victory, the British government became more hesitant towards supporting the CSA. To further make the British conflicted; Abraham Lincoln passed the Emancipation Proclamation, which freed all slaves in areas that were engaged in active revolt (the CSA). This made it politically more difficult for Britain to back the CSA, as Britain had abolished slavery a few years prior. The Emancipation Proclamation was unable to break the south economically, because the slaves would not be able to find out they were free until after Union forces conquered the slaves region. The whole freeing the slaves deal was more a political move than a moral one, although it did give the population a moral reason to back the war.

Hopefully that answers your questions, if not, let me know. Feel free to ask more of your questions, as I would be happy to answer them.

Edit: Removed claim that Slavery is contested as a partial cause of Civil War