Tavis Smiley frequently says (and I agree with him on that point) that Dr. Martin Luther King is the greatest American we ever produced. The most important man in contemporary Black history next to Carter G. Woodson or Dr. Martin Luther King I would argue is John H. Johnson.
John H. Johnson is the Arkansas born man from humble beginnings. His father died in a sawmill accident in 1926. His mother Gertrude saved her money in order to move herself and John to Chicago. Upon their arrival in Chcago in 1933 he was enrolled at all-Black DuSable High and was exposed for the first time to middle class African-Americans. Some of his DuBale classmates were Redd Foxx, Nat King Cole and entrepreneur William Abernathy. He studied hard during the day and devoured self-improvement books at night. In 1942 he took a $500 loan against his mother's furniture and started Johnson Publishing Company. He launched Negro Digest which was the forerunner to Ebony. By June 1942 the circulation of his magazine was up to 50,000 copies and doubled to 100,000 copies in October 1943 when First Lady Eleanor Roosevelt penned one of his regular guest columns called "If I Were A Negro."
JPC (now run by his daughter Linda Johnson Rice) grew to become the largest black-owned publishing company in the world. The iconic Ebony magazine he founded in 1945 is the nation's number one African-American oriented magazine with a circulation of 1.7 million and a monthly readership of 11 million. Jet Magazine, the newsweekly magazine he founded in 1951 also became a staple in African-American homes. JPC not only publishes books, it produces the Ebony Fashion Fair traveling fashion show and owns Fashion Fair Cosmetics as well. 
Ebony became the African-American version of Life magazine. Without the existence of Ebony, the words of an Atlanta born preacher by the name of Dr. Martin Luther King, Jr. wouldn't have been exposed to millions of people. The early civil rights marches and events would have gone uncovered. In the 80's a Chicago DJ by the name of Tom Joyner was hired to host the Ebony-Jet Showcase TV show. That exposure led to Tom Joyner's radio show becoming a syndicated property that's heard by 11 million people daily courtesy of Cathy Hughes' Radio One.
His wife Eunice Johnson started executive producing the Ebony Fashion Fair shows in 1963. The show is celebrating their 50th anniversary in 2008. The shows proved that not only do African-American women have a unique sense of style and flair, we look good strutting down runways wearing those couture outfits as well. Those traveling shows not only have raised $57 million for local charities, they jump started the acting careers of former Ebony Fashion Fair models Richard Roundtree, Judy Pace and Diahann Carroll.
Before Pat Cleveland became an internationally known supermodel, she strutted her stuff at Ebony Fashion Fair fashion shows during the 60's. Fashion Fair model alumni Janet Langhart Cohen, Sue Simmons and B. Smith used their time there as springboards to greater success in other fields. The Ebony Fashion Fair shows also give Black fashion designers such as Tracy Reese and others a chance to showcase their talents as well.The best selling Fashion Fair cosmetics line is the largest cosmetics company that caters to women of color. Over time it eventually forced white-oriented makeup lines to broaden their products and make shades compatible with our skin tones.
So as you can see, the influence of John H. Johnson and his company have had far reaching ripple effects on not only our culture, but profound effects on our country over the last 60 plus years as well.