You've probably been to the best starting point for this search, the GPS website, https://www.georgiastandards.org . Clicking the orange Georgia Performance Standards tab at the top of the page led me to links about the GPS. There is lots of good current information linked here. Clicking the Frequently Asked Questions link led me to a document with FAQ #2, Why did the curriculum need to be revised? This is a very brief answer about the transition from the old QCC standard to the then-new GPS. It mentioned that the impetus for the revision was an audit of the old QCC by Phi Delta Kappa. I started looking for that audit, which would be a great primary source for this paper.
On www.google.com I searched the terms "quality core curriculum" audit "Phi Delta Kappa" . There are some decent results for this search, each having bits of relevant information, and they should not be overlooked. For example, the GPEE Toolbox: Curriculum and Standards goes back to the establishment of the QCC as a result of a 1985 law. However, none was the detailed document that I knew was out there, so I limited the results to the period from Jan. 1, 2002 (when the PDK audit was released) to Dec. 31, 2005. To choose a date range, I looked to the top of my results, just under the search box, and clicked on Search Tools, then Anytime, then Custom Range, and entered my dates.
Among the first several hits was this one:
Apr 23, 2004 - Phi Delta Kappa International. Eighth and ... Members of the Georgia Performance Standards Audit Team: Dr. William ...... Quality Core Curriculum as revised.
This isn't the audit I was looking for, but it is even better. It is a 2004 audit of the draft of the GPS. It is a reliable primary source that contains a fair amount of history, including the criticisms of the previous standard that led to the development of the GPS.
Regarding the part of the assignment about the CCGPS, the GPS website I mentioned earlier, https://www.georgiastandards.org , has a tab labeled Common Core GPS ELA/Math.You've probably already seen this; if not, it's worth a look. You can find more on the Common Core State Standards Initiative web site, which is linked at the bottom of this page.
One last interesting source is a Georgia Public Broadcasting Education broadcast of the Common Core Orientation held by the GA DOE. This link came up on the second page of results of my Google search of Georgia performance standards .