Where were immigration depots located?

Ports of New York, Boston, Baltimore,  Philadelphia and New Orleans.

Explanation:

US Immigration depots were created between the nineteenth and twentieth century. They were passenger entry points into the United States of America. The first being the in Port of New York which received a greater volume of immigrating passengers. Later on, other ports were opened in Boston, Baltimore, Philadelphia and New Orleans received immigrating passengers from all over the world like the, like, the Russians, Germans, Dutch, Czechs, Swedish and the Irish

Due to public health and sanitary reasons, the mass entry of immigrants led to the control in the mid-nineteenth century of peoples from all over the world  who came in over-crowded ships. Many immigrants were found to arrive sick or dead mostly due to the in-human conditions in which they traveled.  

The US government thus saw it fit to establish an Emigrant Landing Depot at Castle Garden in 1855, to curb the activities of unscrupulous job fraudsters and other criminals known to prey on unsuspecting immigrants who disembarked in search of work and living facilities.The Government  also imposed that sick passengers arriving in over-crowded ships not be allowed  entry into the country and through these controlling procedures captains made available Customs Passenger lists. Based on this list, a documented reference material of the names of immigrants into the United States was created.

world war i began in 1914, after the assassination of archduke franz ferdinand, and lasted until 1918. during the conflict, germany, austria-hungary, bulgaria and the ottoman empire (the central powers) fought against great britain, france, russia, italy, romania, japan and the united states (the allied powers). to new military technologies and the horrors of trench warfare, world war i saw unprecedented levels of carnage and destruction. by the time the war was over and the allied powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

explanation:

simplify brackets

8 - 2a - 7 = a + 40

simplify 8 - 2a - 7 to -2a + 1

-2a + 1 = a + 40

add 2a to both sides

1 = a + 40 + 2a

simplify a + 40 + 2a to 3a + 40

1 = 3a + 40

subtract 40 from both sides

1 - 40 = 3a

simplify 1 - 40 o -39

-39 = 3a

divide both sides by 3

-39/3 = a

simplify 39/3 to 13

-13 = a

switch sides

a = -13