In formal English, the phrase ‘named after’ is used to say how something got its name. But in informal English, the term “named for” is used. It’s clear from the context that the intent is the same.
But which constitutes proper use? In a society where communications have been reduced to 140 characters, casual conversation is considered more inclusive. So, ‘named for’ would be the better choice. But, in a society where reading, writing and comprehension is diminishing, the more formal tense is a bi-product for improved grammar and writing. This would then lean towards ‘named after.’
So when we name that great building, bridge or park in your honor, do you want it named for you or named after you?