By Jim Melwert

PHILADELPHIA (CBS) – It was 225 years ago, today, when the United States Constitution was adopted by the Constitutional Convention here in Philadelphia. And there are all kinds of events in town to mark the occasion.

As the famous story goes, when Ben Franklin, walking these streets in Philadelphia, was asked if the convention formed a monarchy or a republic, he responded, “A republic, if you can keep it.”

Well, here we are 225 years and a few amendments later.

To celebrate the anniversary, The National Constitution Center will offer free admission. And out in front of the center, a massive bouquet, 12-feet wide and 16-feet high is set up.  The floral arrangement is made from materials designed and contributed from artists from 46 states, Puerto Rico and the United Kingdom.

Across the Mall, where it all took place, special events are also planned at Independence Hall.