The statement "northern states made it difficult for former salves to purchase land by requiring slaves to pay ridiculous sums of money," is true.
Slavery in the North never approached the numbers of the South.
Slavery in northern states was abolished in 1804 through a new legislation passed.
By 1804 (including New York (1799) and New Jersey (1804)), all of the northern states had abolished slavery or implemented measures in order to gradually abolish it.
