The <a href='https://en.wikipedia.org/wiki/Chicago_"L"#History' id="mwlw" rel="mw:WikiLink" title='Chicago "L"'>Chicago "L"</a> elevated rail system begins operation.<sup about="#mwt106" class="mw-ref reference" data-mw='{"name":"ref","attrs":{},"body":{"id":"mw-reference-text-cite_note-19"}}' id="cite_ref-19" rel="dc:references" typeof="mw:Extension/ref"><a href="./June_6#cite_note-19" id="mwmA" style="counter-reset: mw-Ref 19;"><span class="mw-reflink-text" id="mwmQ">[19]</span></a></sup>
<span class="mw-reference-text reference-text" id="mw-reference-text-cite_note-19"><cite about="#mwt103" class="citation book cs1" id="CITEREFBorzo2007">Borzo, Greg (2007). <i id="mwBl0">The Chicago "L"</i>. Chicago: Arcadia Publishing. pp.<span id="mwBl4" typeof="mw:Entity"> </span>23, 43. <a class="mw-redirect" href="./ISBN_(identifier)" id="mwBl8" rel="mw:WikiLink" title="ISBN (identifier)">ISBN</a><span id="mwBmA" typeof="mw:Entity"> </span><a href="./Special:BookSources/978-07-38551-00-5" id="mwBmE" rel="mw:WikiLink" title="Special:BookSources/978-07-38551-00-5"><bdi id="mwBmI">978-07-38551-00-5</bdi></a>.</cite><span about="#mwt103" class="Z3988" id="mwBmM" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=The+Chicago+%22L%22&amp;rft.place=Chicago&amp;rft.pages=23%2C+43&amp;rft.pub=Arcadia+Publishing&amp;rft.date=2007&amp;rft.isbn=978-07-38551-00-5&amp;rft.aulast=Borzo&amp;rft.aufirst=Greg&amp;rfr_id=info%3Asid%2Fen.wikipedia.org%3AJune+6"></span></span>