 Despite the controversy over the number of stops and route , a groundbreaking ceremony was held on October 27 , 1972 at Second Avenue and 103rd Street . Construction began shortly thereafter on what was to be the 99th – 105th Streets segment , which was projected to cost $ 17 @.@ 48 million ( worth about $ 98 @,@ 886 @,@ 000 today ) . Construction costs for the entire line were pegged at $ 1 billion ( about $ 5 @.@ 657 billion today ) , and rose to $ 1 @.@ 3 billion ( about $ 6 @.@ 93 billion today ) a year later . On October 25 , 1973 , the line 's Chinatown segment commenced construction at Canal Street under the foot of the Manhattan Bridge ; this segment , between Canal and Pell Streets , was due to be completed by 1980 and was being built at a cost of $ 8 @.@ 3 million ( equal to about $ 44 @,@ 244 @,@ 000 in current dollars ) . Less than a year later , on July 25 , 1974 , construction for an East Village segment of the line started near Second Street , spanning between 2nd Street and 9th Street . Another contract , for a Midtown segment between 50th and 54th Streets , was awarded that year , but construction never commenced . In total , construction on the Second Avenue Line during the 1970s spanned over 27 blocks . A segment between 110th and 120th Streets in East Harlem was also completed at a cost of $ 34 @.@ 45 million ( equivalent to $ 194 @,@ 888 @,@ 000 in 2015 ) . 
