How do you say it correctly in English?

What was Ireland like up until 1973 is grammatically correct - the other version is incorrect. How is asking about an action, what is a person place or thing.

Only the second version grammatically because the construction is:

"what is/was...something...like?"

We use that construction when we ask somebody to describe something, e.g. the weather.

In conversational English you can also use "how is/was something (for you)?" without "like" to ask for a description. So you can say:

What was it like in Ireland up until 1973?

What was Ireland like up until 1973?

or

How was it in Ireland (for you) up until 1973?

(inside information: a lot of grammar teachers consider the third one to be incorrect, but it's very common in spoken English especially when talking about the weather, vacations, etc..., e.g. How was the weather? or What was the weather like? (less common in spoken English))

Also, your question should be "how do you say *this* correctly in English?", not "it".

"This" and "that" are used to draw someone's attention to something (called demonstratives) and once you hav their attention then you use "it", e.g.

Question: "what's this?"

(makes the other person look at the thing/question/etc..)

Answer: "It's a car/bus/train/pen/etc..."

Addendum:

I don't know where Jet (below) learnt English but there's nothing wrong with "up until" which means "from the past and no further than". The "up" is superfluous but not incorrect. Hmm... too many cooks :)

What's the condition of Ireland in 1973?

If this is for a school issue, the "what" would be correct. If you were to be asking the question,, it would be "how was Ireland up until 1973?

try the history of ireland until 1973 or the first of the 2 you have listed

What was Ireland like up until 1973... :)

The second: "What was Ireland like up until 1973?"

What was Ireland like up until 1973?"

it sounds better.

"What was Ireland like up until 1973?"

this is the correct way to ask... you could also ask "How was Ireland up until 1973?", although "what" would get a more tangible answer more than likely.

what was ireland like up until 1973?