Gay rights activists openly marched in Boston's St. Patrick's Day Parade for the first time in the event's 114-year history.

Two groups, Boston Pride and OutVets, were among dozens of contingents taking part in the parade through the center of South Boston, once an insular Irish-American neighborhood near downtown that has undergone gentrification in recent years.

"South Boston is more diverse then it's ever been and our inclusion is a testament to change in the neighborhood," said Sylvain Bruno, president of Boston Pride.

In the past, gay groups were excluded from the parade as organizers said homosexuality was in conflict with Roman Catholic doctrine. However, after pressure to change the position from LGBT activists and those arguing it ran counter to the state's liberal non-discriminatory attitudes, parade organizers reversed the policy.

"Finally in the city of Boston we're seeing the inclusivity we never thought we would see," said Bryan Bishop, the 46-year-old founder of OutVets, representing gay military veterans. "This is personally one of the greatest days of my life."

Not everyone was happy about the inclusion of the groups. Friday, the Knights of Columbus, a Catholic men's group, chose not to participate in the parade, criticizing the event as having become "politicized and divisive."