After a brief sojourn in Virginia, Ludlow returned to Europe, where he was appointed by a commission distributing seized and forfeited property in the aftermath of Oliver Cromwell's conquest of Ireland.

In 1635 Roger Ludlow joined with other Puritans and Congregationalists who were dissatisfied with the rate of Anglican reforms, and sought to establish an ecclesiastical society subject to their own rules and regulations.

The Massachusetts General Court granted them permission to settle the cities of Windsor, Wethersfield, and Hartford in the area now known as Connecticut.

The Connecticut towns decided to send a force of more than 70 soldiers under the command of Captain John Mason, along with Narragansett and Mohegan allies to attack a Pequot fortified village on May 26, 1637.

While Ludlow did not participate in what became known as the Mystic massacre, his role in the General Court meant that he took part in the decision to send the force.

[9] On May 29, 1638 Ludlow wrote to Massachusetts Governor John Winthrop that the colonists wanted to "unite ourselves to walk and lie peaceably and lovingly together."

Ludlow then chose to take leave from Hartford and Windsor and obtained a charter from the General Court to begin a settlement at "Pequannocke" (present day Bridgeport).

He left with a group of like-minded settlers from Windsor, Watertown, and Concord to purchase property along the coast of Long Island Sound west of the New Haven Colony.

While on this task Ludlow recalled the attraction of the salt marshes west of the Pequonnock River near "Unquowa" and purchased land there from the native Sachem and founded the town of Fairfield.

Early in 1640, Ludlow purchased land from the Siwanoy Sachem Mahackemo located still further west in an area that would become Norwalk, Connecticut.

Ludlow settled at Dublin and in November 1654 was appointed to serve the Council as an adjudicator of matters relating to property law.