Is there a limit? I couldn't find one posted.

Have a look at this link** and this one (and this for 2013). A quick summary:
*Excel 365 unverified. **This (web archive) link probably will not work with your browser, but the information is in the page source. 


You can find out how many rows your version of Excel supports by opening a new file in Excel then pressing CTRL + Down Arrow in an empty worksheet. This number of rows can be saved in the default format that version of Excel supports (e.g. XLSX). However, you will not necessarily be able to save in the older XLS format, which is still limited to 65,536 rows. Typing in a cell in row number 1048576 (e.g. A1048576) then saving to XLS format will cause a warning. If you close and reopen this file, you will then find this cell empty. 


Doing a web search for "maximum number of rows in Excel" gives a link (several, actually) with


