Biggie was saying that in 94, Snoop in 93, Jay in 98 and on.TM101 - made people start sayin I'm not a rapper and just a street cat gettin money.
Black Album - As buddens said "the more people said they didn't write shyt, the more it started to sound like they didn't". I know that Jay said that he didn't write his lyrics before this but this is where that concept really took off.
College Dropout - first step to ushering in the skinny jeans, tight clothes and hipster in general.
And people had Skinny jeans in the 80s, 90s and 2000s, and Kanye didn't rock them in 2004. Not a rapper but a hustler who knows how to rhyme is from the mid 90s as well.
Do your homework.

mainstream rap
come on i know all that... I just felt like those were the 3 albums that did those things for the modern generation. I guess the kanye one is a little bit of a stretch, especially since you can say that Jim jones and stack with their fitted movement gave influence to that too.

at men in hip hop wearing skinny jeans in the 80s. They wore pants that fit not from women's department. You had some groups from the old school(75-82) era dress up in costumes like funk acts from the 70s but their was no such thing as skinny jeans. The 90s was when baggy became popular and designers made clothes that could capitalize off the trend.