Person A and B can best be classified as:

a system of cooperative federalism emerged, as the powers of the federal government expanded.

the viking voyages took place during the middle ages, which was about this time. 500 to 1350. the viking voyages took place during the middle ages, which was about this time.

in the 1900s, the united states was still a largely agrarian society with a very fast growing industrial and manufactering sector.

the south of the country was the bread basket of the country with large farm lands making up a majority of the economy.

in the north and more specficially north-west, growing manufactering and export sector had made the united states into a powerful exporting country.

this peaked in the 50s and 60s when the united states became the largest economy in the world and the largest exporter.

today, the majority of the united states economy is made up of the services sector that includes banking, insurance, music, movies, hotels etc.