I have 2 questions about those 2 equations. 1-) Which one came first in the history of electromagnetism? Some articles say: Biot-Savart derived their equation from Ampere's Law. Some say: Ampere derived from Biot-Savart. Which one is true? 2-) Since Ampere is special form of Biot-Savart and Biot-Savart is more general form. Why didn't Maxwell chose Biot-Savart instead of Ampere? Why is Ampere's law stated as one of Maxwell equations instead of Biot-Savart?