Improved mass-production techniques affected the american economy of the 1920s by —

less cost of manufacturing, and higher output of the product, hence, more for less cost, meaning they could be sold cheaper.

Explanation:

assuming that you are talking about the one in egypt: hecka oil

explanation:

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.