What did ancient mesopotamia offer early people that encouraged them to settle and build civilizations?

Which of the following was probably the most difficult challenge facing construction of the railroad?

What were three advantages the north had in the civil war? it was fighting most battles on home ground. it had a greater number of soldiers. it had more highly skilled military leaders. it had a stronger navy. it had a better network of railroads. pick three .

Which of these events was a severe setback for the u.s. war effort in the pacific?