University of Durham became a very curious federal institution in 1908 – its Durham division was itself collegiate, while its Newcastle division had two independent colleges (Armstrong College, the civic university college affiliated to Durham since its creation in 1871, and the Medical College, which had been affiliated since the 1850s). The two colleges of the Newcastle division were merged in 1937, and Newcastle finally became an independent university in 1963. Similarly, the university college in Dundee, founded 1881, became a college of the University of St Andrews in 1897 before becoming an independent university in 1967. The idea of the residential college spread to America in the early 20th century, with Harvard and Yale both establishing colleges (called "houses" at Harvard) in the 1930s. Like the Durham colleges, these were colleges established and owned by the universities with only limited involvement in teaching. The American state university systems also developed federal-style universities with autonomous campuses (although normally not legally independent). As these systems often developed from a single original campus, this often became identified as the 'flagship' campus of the state system. Types of collegiate university An early typology of British university institutions by the Principal of the University of Edinburgh in 1870 divided them into three types: collegiate (Oxford, Cambridge and Durham), professorial (the Scottish universities – St Andrews, Glasgow, Aberdeen and Edinburgh – and the new colleges in Manchester and London) and non-teaching examination boards (London). However, even at that time drawing hard lines was difficult: Oxford had, until a few years prior to this, been an examination board for its colleges, and Trinity College Dublin combined elements of the collegiate and professorial styles. More recently, the collegiate and federal traditions have been seen as separate in Britain, although both inspired by different aspects of the colleges at Oxford and Cambridge, e.g. "With the partial exception of Durham (and in the twentieth century York, Kent and Lancaster) there has been no serious attempt to create in Britain a collegial tradition in the mode of Oxbridge, but the federal principle has been widely emulated." Similarly a conference on The Collegiate Way in 2014 concentrated entirely on universities with residential colleges (e.g. Oxford, Cambridge, Durham, etc.), making no mention of federal universities. This was in keeping with the idea that "The collegiate way is the notion that a curriculum, a library, a faculty, and students are not enough to