history - Was the fast of Tisha B'av in effect during the second temple era?

As the Beis Hamikdash was rebuilt at that time was the fast of Tisha B'Av in effect during the Second Temple Era?

Answer

This is a matter of dispute between the Rishonim.

The Rambam in his commentary to the Mishna (Rosh Hashana 1, 3) wrote that the people observed the fast of Tisha b'Av even during the period of the second temple. http://www.hebrewbooks.org/pdfpager.aspx?req=37942&st=&pgnum=202

However Rabbi Shimon ben Tzemach Duran (Shut Tashbetz 2, 271) wrote that they did not. http://www.hebrewbooks.org/pdfpager.aspx?req=1381&pgnum=217

Apparently, this is also the view of Tosefos (Taanis 12a "Hatam") as explained by Rabbi Avraham of Minsk (Quoted In Sedeh Tzofim, see paragraph beginning 'Gemara') http://www.hebrewbooks.org/pdfpager.aspx?req=37037&st=&pgnum=179&hilite=