On June 17, the Senate voted by a 76 to 18 margin to adopt the bipartisan substitute worked out by Dirksen in his office in May and to give the bill its third reading. Two days later, the Senate passed the bill by a 73 to 27 roll call vote. Six Republicans and 21 Democrats held firm and voted against passage.
From a quick search I did I found this at http://www.congresslink.org/civil/essay.html
That's great, but I have another question. If I understand your description, after the House voted in February, the bill was altered (you mention that the Senate passed a "bipartisan substitute" in July). That would render the February House vote moot because the bill had changed (or was amended). If so, did the House vote again on the final version of the bill? Or am I incorrect that the bill in July was different than the bill the House voted on in February?