Why did they do this?

To accomplish certain tasks easier than could be done alone.

#FOUND5

Related questions

#REV34 Why did the states decide to create the Union? (Colonies, Revolution, and Union) The states discovered that they could better accomplish several vitally important tasks by working together, creating a general and central government to help the states achieve this cooperation.
#FOUND1 In what country do you live? (Foundations of the Republic) In the United States of America.
#FOUND2 Why is this country called the United States of America? (Foundations of the Republic) Because it is made up of a number of States which were once separate, but afterwards agreed to unite together for specific purposes.
#FOUND3 What is meant by "state?" (Foundations of the Republic) By "state" is meant any district or country whose people are all under a common government.
#REV32 What was the change produced by the Revolution? (Colonies, Revolution, and Union) The different Colonies became each a free state, having power to govern itself in any way it should think proper.
#REV33 Had not one state any power over the other? (Colonies, Revolution, and Union) Legally, each state was an independent, autonomous and sovereign entity.
#FOUND4 Had then the different States which united together each a government of its own? (Foundations of the Republic) Yes; but they agreed to put themselves all under one general or federal government.
#POW159 Does a state have the right to secede from the Union of States? (Powers of Congress) Yes. States may - constitutionally - join themselves with other states at their will, and their involvement in the union should not be coerced. The Constitution could have stipulated the Union was to...
#POW160 What should the Union do if a State wishes to secede? (Powers of Congress) The Union may try to amend whatever grievance the state has against the Federal Government, or may revoke benefits bestowed to the state on behalf of the Federal Government, to persuade them to stay....
#EXE180 Why did the States delegate these powers to the Federal Government? (Presidency and Executive Power) In order to aid and assist in a more consistent governance among all the people known as Americans.
#RGTS331 Is there a flaw in the Seventeenth Amendment? (Rights and Amendments) The founders designed the House of Representatives to be the House of the People, popularly elected and promoting the welfare of the People. However, Senators were to promote the welfare of the State...
#REV35 What approach to government and law did the states first create in order to work together? (Colonies, Revolution, and Union) They drafted the Articles of Confederation.