Why would imperialists want to aquire certain colonies?

They would gain access to a big amount of raw materials and other goods for trade and wealth generation. This would increase the power projection the imperialist nation would have in comparison to other imperialist nations. With more colonies came bigger navies and with bigger navies came more trade and wealth. This made big imperialistic nations extremely powerful especially Britain or Spain.

in the 1950s, country music came into its own before rock-n-roll took off in the 60s while jazz and classical music continued to innovate

the northwest ordinance of 1787 guaranteed basic rights for settlers and banned slavery there.