Chareidim have been around since, either, Avrohom Avinu or Moshe Rabbeinu; depending whether you start counting from pre-Matan Torah or post-Matan Torah.
What is today called Chareidism is what used to be called Judaism; much as what is today called Orthodoxy is what used to be called Judaism. They are simply the default Judaism that never broke away. When the Reform broke off, the new movement called the original Judaism — Orthodox; when the MO broke into their own movement, they called the original Judaism — UO/Chareidi.
Clothing don’t make the man; I have no idea why you are harping on how who dressed when, when attempting to make artificial distinctions between how Jews dressed before the Reform and/or MO versus thereafter. Clothing changes over time; that has nothing to do with the practice of Judaism.
That being said, what absolutely is true is that Jews dress as Jews, even if what it means to dress as a Jew may change with time. Practicing, observant , Jews do not dress as the Gentiles. Just as the Navy uniform was different 200 years ago from 100 years ago, and again 100 years ago from today, doesn’t mean that they aren’t the same Navy. If a Sailor today decided to toss today’s Navy uniform for that of what the Navy wore 100 years ago or 200 years ago, it won’t help his defense at his court martial when he defends himself saying he was wearing the original Navy uniform.
A Jew, too, needs to dress in the uniform of the Jew today.
And with that, let’s conclude by pointing out that the mode of dress of Chareidim such as the Vilna Gaon and his Talmidim who settled in Ottoman Palestine as well as Chareidim such as the Talmidim of the Baal Shem Tov who settled in Ottoman Palestine, (all of whom continued their presence in Eretz Yisroel into the British period and the Zionist period) as well as how Chareidim like Rav Yosef Chaim Sonnenfeld dressed both in the Ottoman period and in the British period, are easily recognizable and comparable as how Chareidim dress today during the Zionist period.