The simple answer is no. If you are in high school/secondary education, your instructor may allow it, but anything at the college/university level should not allow it and probably doesn't. If it is truly a basic fact such as Pearl Harbor was bombed on December 7, 1941, you don't need a citation for that event. If you are discussing the American entry into the war, then depending on the detail and the relevance to your appear, you should probably have a basic source for this. If you don't have your hands on a published overview history of the war - or whatever it takes - then find a website that will work. Do not use wiki, but look for a university website that provides the history you need and seems reputable.

I hope that helps - good luck.

Encyclopedias aren't exactly considered bastions of authorative knowledge anymore. There are enough university or government run webpages of good repute that books of general knowledge are terribly impractical. But as with any source, it depends on how basic it is and who your audience is. If I'm writing for an archaeological journal, I don't need to cite that the lowland Maya lived in modern Yucatan, Belize, and Guatemala, or that the Classic Maya period was over by 1100 AD. If this is a highschool World History class, I would probably need to. Odds are though, you can find a cursory book on the subject at yor library. That's probably where the encyclopedia got its info. A more specific fact, like the modern population of Mexico, will always need a reference, but you have no reason to use an encyclopedia when the official Mexican government website has the most recent information avaiable with a quick Google search.

If you're explicitly going for the popular narrative of an event, then encyclopedias might come in handy. But again, they are an outdated medium that hardly reflect present knowledge, scholarly or popular. An encyclopedia will always be informayion processed through several levels from its source. Here it might be better to make your point by referencing history as related in an otherwise respectable news article or broadcast, as told on a popular YouTuber's history, as depicted in a feature film/TV show, or even as presented in a top reddit post. These are "primary" sources of popular historical narrative available to anyone with an internet browser. I've often found it useful to use "metadata" as well. Wikipedia only has a paragraph on this entire culture, what does that tell us about heritage awareness? r/AskHistorians has received 30 questions about this topic in the past week, and that tells us what people know/think about it.

TL:DR There's no reason to use a tertiary source encyclopedia when the internet makes primary and secondary resources so available.

Do you mind sharing your topic so we can help you find better sources?

What about encyclopedia britannica online? I've cited that in my BA in history from Kings College London and not been criticized for it. I used it mainly for facts that were slightly to obscure to be uncited, but not worth finding a book or journal article for...

While encyclopedias are typically not good sources themselves, they are an excellent tool for finding sources. Most encyclopedias will list where their information is from, and they tend to use reputable sources themselves.

This isn't just encyclopedias either. Anytime you want a source, but the text you are reading isn't reputable or seems too far removed to cite, try reading that sources sources!