What was the name of  president of America during the civil war ?

Who among the following was the first to arrive in Africa as traders that eventually led to European colonization of Africa?

Due to which of the following factors, the Industrial Revolution took place in England in the eighteenth century?
$1.$ The discovery of coal and iron deposits
$2.$ The discovery of steam power
$3.$ The introduction of railways
$4.$ The regular supply of raw materials

Select the correct answer using the code given below:

Which Arab scientist could be given the credit of christening the mathematical discipline of algorithm?

Which one of the following developments took place because of the Kansas-Nebraska Act of $1854$?