The reason for this is that many of the provisions of the Constitution are much more conservative and less radical than the principles of the Revolution, as seen in documents like the Declaration of Independence.

Because the leaders of the Revolution needed mass support for their movement, they emphasized such things as democracy and the equality of all people.  These ideas were largely followed by the governments under the Articles of Confederation.  But this system did not seem (to many of the elite) to be working and so they pushed for a new constitution.

The Constitution of 1787 was much less democratic than governments had been under the Articles.  The Constitution, for example, only allows the people to vote directly for one part of the federal government.  Under the Constitution (before amendments) the people only voted for the House of Representatives while the President, the Senate, and the Supreme Court were selected without direct public input.  There were also provisions of the Constitution that limited what state governments could do, like creating laws that would forgive debts (Contract Clause).

In short, the Constitution was meant to some extent to take power away from the people so there would not be as much democracy.  It was not trying to create a monarchy or a dictatorship, but it wanted more room between the people and government so the government could do what it knew was best rather than following the whims of the people.  This represented a move away from the democratic ideals of the Revolution.

It is for this reason that Henry said the Constitution was a counter-revolution.

According to Patrick Henry, "The Constitution represented a counter-revolution." Assess the validity of this statement.

I think that Henry's fundamental idea is that there is a difference between declaring independence and securing it.  In this, the Constitution could be seen as opposite of the spirit of revolution.  Whereas Sam Adams' group of revolutionaries like the Sons of Liberty reveled in creating disturbances and public unrest, these actions ended up being strongly discouraged by the Constitution.  For a nation that prided itself on being radical and causing disruption to the British manner of ruling, the Constitution represented a moment where the framers understood that they had to embrace establishment forms of power in order for the nation to survive.  The intensity and zeal of the revolution was replaced by the Constitution's goals such as ensuring domestic tranquility, promoting the general welfare, as well as ensuring that questioning authority was done in a manner that utilized institutional channels and adhered to rules outlined in the document.  For individuals like Patrick Henry that held so much faith and professed so much loyalty to individual freedom and liberty, the Constitution's assertion of a national government seemed to be an embrace of goals that were antithetical to the spirit of the Revolution.  Henry's belief of "Give me liberty or give me death," is a spirit that helped to inspire the Revolution.  Yet, in the face of the Constitution, such zeal and passion would fly in the face of the established goals and principles of the document.  In this light, the Constitution could be seen as counter- revolutionary.