The length of time it actually takes to get a copyright depends on a variety of factors. Almost anyone that gives a reasonable time frame to be expected are mostly considering people whose application are fully prepared and get accepted on the first try. In reality, there are many people that are in initial stages of determining whether or not a copyright is even appropriate for their situation and how they should go about filing. Consequently, not everyone prepares significantly enough to convince the office of approval, and they may have to request reconsideration. In these cases, extra weeks and months may be necessary to find and spend the time, with an attorney if necessary, to get everything organized appropriately and reviewed by the government.
Once the appropriate documents and payments are sent to the US Copyright Office, there is a waiting period until receipt is acknowledged. This is nearly instant for online applications; however, it often takes more than one month to hear back from paper filings. Once the claim arrives to the office, it is placed into a queue so it can be processed according to the order in which it was received. It is often claimed that the processing time is around 3 months, but it can be more like 4 or 5 during the busier filing seasons.
If your first application is rejected and you want to appeal this ruling, you can request for first reconsideration up to 3 months after receiving your initial ruling. Once the office receives this ruling, you can expect to have a similar waiting period as before. Proposals that get two rejections can be reconsidered a second time. As you can see, the entirety of this procedure can vary widely in length.