ɪn nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi sˈɛvən, ðə nˈuːli fˈɔːɹmd mˌɛtɹəpˈɑːlɪtən tɹˈænsɪt ɐθˈɔːɹɪɾi ˈɛm.tˈiː.ˈeɪ.dᵻsˈaɪdᵻd tə bˈɪld tə lˈɪn æz ɐ ɹˈæpɪd tɹˈænsɪt lˈaɪn, ænd kənstɹˈʌkʃən bɪɡˈæn ɪn ɑːktˈoʊbɚ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi ˈeɪt.
In 1947, the newly formed Metropolitan Transit Authority (M.T.A.) decided to build to Lynn as a rapid transit line, and construction began in October 1948.