From Cape Cod in the east and the Berkshires in the west, all roads lead to Boston. Described as "the thinking center of the continent" by Oliver Wendell Holmes in 1859, the Boston area is home to some 50 degree-granting institutions. A historic park in Lowell recalls the 19th-century heyday of the textile industry. Medical researchers in Worcester, the state's second largest city, developed the birth-control pill during the 1950s. Recession hit the state hard in the late 1980s after a biomedical and high-tech boom earlier in the decade. Once-polluted Boston Harbor, where Puritans landed in 1630, has seen a dramatic turnaround following a $4 billion cleanup project.