What scientific advancement did the chaldeans make

The scientific advancement that the Chaldeans made was the development of a new empirical method to Astronomy (the study of celestial objects).

Explanation:

The Chaldeans were people who lived in Chaldea (Mesopotamia) around the 10th century BCE, before being assimilated into Babylonia. The astronomers that lived here started studying and recording the movements of the moon, planets and constellations to try and explain the natural rules of the universe and their beliefs. This became their "empirical" approach, since they used their senses to receive information (observation of patterns and behaviours).

b.   jim crow laws were enacted in northern states.

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.