When I went to download my transactions, I saw it is limited to the past 30 days. I needed to download 90 days' worth of transactions from Bank of America into Quicken. As other posts have said, Bank of America no longer lets you download QIF files directly.
Here is the workaround that I used to not have to manually enter hundreds of transactions:
Under the "Activity" tab on Bank of America's website, I downloaded the missing months as a Microsoft Excel Format file (the only file type available in the dropdown). This downloads the transactions as a .csv file. I then used this free online website to convert the .csv to a QIF-formatted file. Within Quicken, under "File" then "File Import," you can import these QIF files of missing transactions into your ledger.
Just posting in case it helps someone else.
[Edited-Readability]
