Boston was one of the first US metropolises and the heartland of US independence war (some Lithuanians, deeply pro-freedom, also joined the fight for US cause there). The extensive Boston Lithuanian community, however, dates to late 19th century when the city was 5th largest in the USA. Its numbers mushroomed in some 1904. There were so many Lithuanians that a demonstration at Boston Commons urging the USA to recognize newly independent Lithuania attracted 5 000 in the year 1919.
In South Boston, traditionally the heartland of Lithuanian community, there is Boston Lithuanian Citizen's Club (368 West Broadway) which houses a Lithuanian food bar and an auditorium for events where the bands from Lithuania have their gigs. This district also has a Lithuanian Saturday school, ethnographic bands, self-support community, credit union and local groups of Lithuanian organizations (Scouts, Knights, Ateitininkai).
The last remaining open Lithuanian church in Massachusetts is also located in South Boston, 75 Flaherty Way (others were closed down ~2009). Built in 1901 it is dedicated to St. Peter. The parish was established in 1896 through a hard struggle as the Irish community then dominated South Boston and Irish bishop Williams opposed the move. In 2008 the parish had 1000 member families, 100 of them newly immigrated and 900 descendants of earlier immigration "waves". Lithuanian and English mass are both celebrated.
Previously other Boston conurbation areas had their Lithuanian churches as well. Immaculate Conception church of Cambridge (432 Windsor Street) has been built in 1913 and has been recently transformed into "affordable housing" by the "Just a Start Corporation". This corporation acquired the building in 2007. A municipal commission formed in 2009 deemed it to be of great significance as an example of Mission Style / Arts and Crafts (created by famous Maginnis and Walsh company) and for its possible inspirations in the Gothic architecture of Lithuania. It asked not to alter facades (was unaltered) and not to remove religious references where possible (crosses were however removed and frescoes whitened). The owners were however given a free hand in the interior which was entirely changed.
The Boston area's third Lithuanian church was the white St. Casimir in Westfield (38 Parkside Av). Since its closure in 2003, it has been sold to the school system and used as a school for kids with ADHD. St. Casimir name remained however as the parish was unified with St. Peter (Slovak) to form St. Peter's/St. Casimir's parish. The congregation now prays at the former Slovak church, however (24 State Street), and only the US flag remains waving.
Boston is also famous for the Lithuanian encyclopedia first published there in 1953-1966 (nicknamed the Boston encyclopedia). This 37 volume work is still the largest encyclopedia ever published in the Lithuanian language. At the time Lithuania had been occupied by the Soviet Union so there was no state funding and many sources were very hard to access making the job undertaken by some 200 Lithuanian American authors even more tremendous. The authors wished that liberated Lithuania would have its encyclopedia and their work is indeed still used. In 1970-1978 they translated the Lithuania-related articles to create 6 volume English "Encyclopedia Lituanica", still the most comprehensive English work on Lithuania.
Lithuania's Jews also moved to Boston before World War 1 forming the community of "Anshei Vilner" (Yiddish for "People of Vilnius"). Their modest synagogue (Vilna Shul) was built near the Boston Commons. It was abandoned in 1985 after the Jews left the district but unlike many other similar buildings, it was saved from demolition. It has since been repurposed as a museum which offers a chance to return back in time to the era when Jewish communities were poor.