What event made it necessary for brokers to work on sunday?

The previous week had been a record-breaking week for the market and brokers were trying to get caught up before Monday.

the constitution of the united states gave congress the absolute authority over immigration laws

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.