While not necessarily restricted to a time period, these poems are more of what you'd expect to find in a literature class or studied explicitly as a "classic". While I think many people relate more to poetry written now and written with fewer restrictions, I personally found a lot of inspiration and resonance in more antiquated pieces, especially as I was just starting to get into poetry.

"Bright star, would I were stedfast as thou art"... | Poetry Foundation

I Sing the Body Electric by Walt Whitman | Poetry Foundation

To -- -- --. Ulalume: A Ballad by Edgar Allan Poe | Poetry Foundation

Hymn to Intellectual Beauty by Percy Bysshe... | Poetry Foundation

I Wandered Lonely as a Cloud by William Wordsworth | Poetry Foundation