Georgia were to the point when setting out why they were declaring secession:
The people of Georgia having dissolved their political connection with the Government of the United States of America, present to their confederates and the world the causes which have led to the separation. For the last ten years we have had numerous and serious causes of complaint against our non-slaveholding confederate States with reference to the subject of African slavery. They have endeavored to weaken our security, to disturb our domestic peace and tranquility, and persistently refused to comply with their express constitutional obligations to us in reference to that property, and by the use of their power in the Federal Government have striven to deprive us of an equal enjoyment of the common Territories of the Republic.
So their complaint was not just that the north was refusing to comply with their obligations to property (slaves), but that it was impossible for slaveholders to travel with slaves in the northern states without risking losing them.