names crossing gender lines in the past!

I was looking at ssa lists from the early 20th century and found this surprising trend:

girls named [name]John[/name], [name]William[/name] & [name]Robert[/name]

boys named [name]Eva[/name], [name]Martha[/name] & [name]Mary[/name]!


has any one else seen this or know anything about this surprising trend from the past? Makes me feel like the hard edges of gendered names are more contemporary than we think!

Actually most of those are errors from the SSA (in the pre-computer days there would often be enough mistakes for the more common names to appear in the other gender’s Top 1,000).