Southern believed that slaves were their property, and that they had the right to take them with them. So when they noticed that Lincoln was going to abolish slavery they decided it would be best to secede than not have anything to make money from. After the compromise of 1820 they limited slavery to the south, which would split the country into two for the next forty years. The South would feel that slavery was the best thing for the slave for it gave them something productive to do. The North however as a majority felt slavery as a horrible thing by the cruel ways the slave owners would treat and beat their slaves. There were also those who went and helped free and bring slaves up to the North and also into Canada. (Document 1).
Lincoln promising to abolish slavery played a big role on secession. Southerners economy depended on agriculture, and cotton was one of their major crops. So they needed slaves to work in their fields. When they heard that Lincoln would abolish slavery they thought If Lincoln were president¦the Union would be endangered from that hour. (Document 3). The South started to think that it is Better leave the Union in the open face of day, than be lighted from it at midnight by the [arsonists] torch. (Document 2) They also said that All citizens of the United States have an equal right to settle with their property in the Territory, without their rights, either of person or property, being¦impaired¦
It opened our eyes to the fact that there were two hostile elements in the country, and that if we allowed slaves to enter any territorial acquisition, our free labor must be excluded from it. (Document 5) They argued about this for a reasonable time until the south eventually seceded from the south.
We really dont know what really caused secession. Even researchers cant solidly say what the cause of secession was. But people can infer, and with clues, can have an idea of what caused secession.