How long does it take to build federalism ?

 A brief reminder about U.S. history  teachs us building federalism took 14 years, with a military war as a booster for this process :

Tensions between American colonials and the British during the revolutionary period : 1760s and early 1770s.

American Revolutionary War : 1775 to 1781. 

• The Continental Congress established a Continental Army under the command of George Washington : June 14, 1775
• The Congress adopted the Declaration of Independence : July 4, 1776.
• After the British defeat by American forces assisted by the French and Spanish, Great Britain recognized the independence of the United States: 1781

The Articles of Confederation established a weak confederal government that operated from 1777 until 1789.

Those wishing to establish a strong federal government with powers of taxation organized a constitutional convention in 1787. 

The United States Constitution was ratified in 1788.

The new republic's first Senate, House of Representatives, and president —George Washington— took office in 1789.

These steps and speed have to be compared with similar current EU federalism process and speed, with currently a monetary war as a booster. This process is the birth of the new Euroland sovereign. Humans are not born in a single minute, and a new sovereign entity is not born in a single year, even taking into account the pregnancy or gestation period.