I had location history enabled for Google Maps and didn't know it. I found it interesting to see which spots Google logged for me over the past week or month, and I don't plan on disabling the service. It's nice to know, however, that I can delete portions of my location history or all of it, as well as disable the feature from tracking me in the future.
To see if you have location history enabled, head to the Google Maps Location history page. Click the gear-icon button to access History settings. Here, you can choose to disable or enable the service.
Disabling location history, however, does not remove your past history. If you'd like to erase the locations Google has stored for the past 30 days, head back to the Location history page. The default time period shows location history for the current day, so you may not see any plots on the map.
Use the pull-down menu below the calendar on the left to show your history, up to 30 days. If you choose a time period in which Google has tracked your location, you'll see the points where you've been on the map. And below the calendar, you'll see options to delete your history from the time period you have chosen or to delete all history.
You can also delete a specific location from your history. Click on one of the red points on the map, then in the pop-up window click "Delete from history."
For iOS users who want to disable Google from using location services, follow this path: Settings > Privacy > Location Services, and turn the slider switch off for Google Maps. For Android users looking to prevent Google from using location service on their mobile device, this Google Support page has instructions.