As Arnold indicated, for your benefit and practice, do check the headers.
But in this particular case, I can tell you without the headers this is a scam.
For starters, the typical elements of the scam setup are here--alone in the world, single father, lots of tragedy in life, doesn't care about age or income, already romantic in initial email...
If the author claims to be from an English-speaking country, one of the first things I look at is the writing. Is it consistent with who/where the person claims to be? I am not expecting perfect grammar or spelling--but are the types of errors made consistent with someone who was born and raised in the country they claim, or are they more consistent with someone who does not really know the language? Is the writing style consistent throughout the email, or are there distinct variations in style and/or grasp of the language?
This person claims to be an American in the military. The English is not consistent with the claim. Here are just a few of many examples.
As you might have known is a tense error and is a strange error for an American to make. It is, however, very consistent with an African, as tenses are one of the most difficult aspects for them to learn.
was the eldest in a family of 2 This statement is definitely not consistent with an American. Besides the tense confusion again, when is the last time you heard or saw an American use the word "eldest"? There are other examples throughout the email of phrases not consistent with American English (authors who don't know English well often mix up American and British terms.) A few other mistakes of the same kind:
cinema, cancer of the breast, going on holidays.We lived in a small land area Not sure what this is supposed to mean, but definitely not consistent with an American.
my late dad worked for the State of IL for income. Africans also have difficulty grasping capitalization rules, and tend to frequently miss the pronoun "i" while inappropriately capitalizing other words, especially job titles and random nouns like state. Also, the verbiage is once again suspicious. While not impossible, "my late dad" is pretty improbable phrasing. The word "late" is rarely used in casual communication--and someone who uses it will have a more formal writing style--he/she would be much more likely to use "father" and "mother" rather than "dad" and "mom." An American would have left off the last 2 words in the sentence, too.
There are a couple of places where the English is distinctly better, suggesting a cut and paste--so I like to google some of those areas to confirm. Check out some results here:
http://www.google.com/search?q=%22I+always+try+to+be+respectful+to+my+partner+and+not+take+them+for+granted.%22&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-ahttp://www.google.com/search?q=%22I+don%27t+care+about+traditional+matching+characteristics%22&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-aAssuming you are still in contact with this scammer, the best thing you can do now is cut off contact. Do not answer his emails or any chat requests. If you are already in phone contact, don't take his calls, or better yet, block his number. Do not tell him you know he is a scammer, and do not point out these or any other errors that help to give him away. If you do so, he will improve his format so he does a better job of fooling his next potential victim. We never want to help scammers to improve their scams.