Tech for a New Series

Advice needed!

I'm starting a new fantasy series, and I need to decide whether to make the technology steampunk (mid-19th century) or 1950s/'60s.

The theme is on social change and fighting for your rights, and those two eras (mid-1800s and mid-1900s) are the two periods in American history that really expounded on that. But I can't choose which one to go with! 

Please vote. Thank you!