Times have changed and most people no longer use physical maps or TomTom's to get where they need to go anymore. They use their smartphones with map apps such as Google Maps and Apple Maps and a myriad of others that rely on those two. Google and Apple will not update the information for your post themselves, it is up to you to update the information, and that could drive to people to your post.
What information do you need to update?
Post name: Most of the time, if your post is listed, it is listed as "American Legion." While that is a start, it can make it difficult for people to find a specific post. You need to add your post number and maybe even the full post name.
Post hours: You don't want people showing up before a post opens, right before a post closes or on days the post is closed.
Post website/Facebook page: The default for most posts on Google Maps is Nationals website. Adding your Facebook page or website helps get your followers and build a sense of community within your post. It is also a great way of keeping everyone up to date about events at your post.
Here are some guides on how to update your post information on Google and Apple Maps. You need to do both maps separately.