Connecticut was known as the “Freestone State” in the 19th century. There were many freestone quarries throughout the state.
 
“Freestone State” has been cited in print since at least 1844. The Byram (CT) Quarry (now closed) provided stone for the Brooklyn Bridge and the pedestal of the Statue of Liberty.
   
     
Wiktionary: Freestone State
Freestone State
1. An unofficial nickname for the state of Connecticut in the United States of America.
   
24 February 1844, New York (NY) Herald, “Important Election in Connecticut,”
They shout that the “Freestone State” is on fire. There must be an intense heat in Connecticut to make freestone blaze like hickory.
 
20 September 1844, Boston (MA) Daily Atlas, pg. 3, col. 5:
He came from the Free-stone State, daughter of the old Bay State, ...
 
December 1846, The Eclectic Magazine of Foreign Literature, “AMerican Nicknames, pg. 567:
Connecticut…Freestone State.
   
Chronicling America
17 February 1854, Daily Evening Star (Washington, DC),  pg. 4, col. 1:
FANCY NAMES OF STATES.—New York is called the Empire State; Connecticut is called the Freestone State, and sometimes the Land of Wooden Nutmegs; ...—New York Sunday Times.
 
Google Books       
January 1865, The Ohio Educational Monthly, “Antonomasia in Geography” by W. D. Henkle, pg. 15:
...  Connecticut, “Land of Steady Habits,” the “Freestone State,” and the “Nutmeg State;” ...
 
Google Books
Americanisms;
The English of the New World
By Maximilian Schele De Vere
New York, NY: Charles Scribner & Co.
1872
Pg. 658:
The valuable quarries of freestone, to which the State-is largely indebted for its revenue, have procured for it the name of the Freestone State, while at other times it appears as the Nutmeg State, from the famous speculation in wooden spices, ...
 
Google Books
The People’s Dictionary and Every-day Encyclopedia
Compiled by William Ralston Balch
Philadelphia, PA: Thayer, Merriam & Co.
1883
Pg. 264:
FREESTONE STATE, the State of Connecticut, sometimes so called from the quarries of freestone which it contains.
 
Google Books
The Family Cyclopaedia of Useful Knowledge:
Cincinnati, OH: Forshee & McMakin
1889
Pg. 489:
Freestone State, the State of Connecticut, sometimes so called from the quarries of freestone which it contains.
 
Google Books
Universal dictionary of the English Language
By Robert Hunter and Charles Morris
New York, NY: Peter Fenelon Collier, Publisher
1897
Pg. 5343:
Connecticut. Land of Steady Habits.  The Freestone State (from its freestone quarries).
 
3 January 1954, Rockford (IL) Morning Star, “Connecticut’s Name Was ‘Freestone State’” (AP), pg. 2B, col. 5:
Freestone is any stone, but especially sandstone and limestone, which may easily be cut in any direction without splitting. Many of the lighthouses along the Atlantic coast and the base of the Statue of Liberty in New York harbor are of Connecticut freestone.
 
Google Books
On This Day in Connecticut History
By Gregg Mangan
Charleston, SC: The History Press
2015
Pp. 88-89:
Other nicknames attributed to Connecticut through the years have been the “Freestone State” (due to the abundance of Connecticut brownstone in national construction projects) ...