in 1853，andrew carnegie met thomas scott，a young su-perintendent of the pennsylvania railroad.the railroad acted oncarnegie's suggestions and did build its own telegraph lines.scottasked andrew to operate the new telegraph and to be his assistant inthe office.andrew accepted.the pay was＄35.00 a month andbesides，it offered andrew a wonderful opportunity to rise in theworld.
in 1862，he organized the keystone bridge company to buildthe first iron bridge across the ohio river .in 1873 he establishedthe j.edgar thomason steel mill .
the new mill was a success from the start.in 16 years moresteel was made in the united states than in england，where it hadbeen made so much earlier.in 1888 andrew carnegie bought acontrolling interest in a company almost as large as his，and inseveral other steel mills near pittsburgh .he joined all thesedifferent companies into the carnegie corporation .this organi-zation included mines，steel mills，ships，and railroad lines tobring material into pittsburgh from all over the country and to takethe finished steel out again.the carnegie corporation ownedeverything needed to make and to distribute steel.in 1901 hiscompany，valued five hundred million dollars，was sold to theunited states steel corporation，formed by the famous americanbanker，john pierpont morgan.mr.morgan then said that carnegie was“the richest man in the world”。he had come from＄1.20 a week to this.
1853年，安德鲁·卡内基遇到了宾夕法尼亚州铁路的一位年轻主管托马斯·斯科特。铁路局听从卡内基的建议，建起了自己的电报线路。斯科特请安德鲁管理新电报机，还请他在自己的办公室作一名助理。安德鲁接受了。工资是每月三十五美元，除此之外，它还给安德鲁提供了飞黄腾达的绝好机会。
1862年，他创办了基斯东桥梁公司，承建横跨俄亥俄河上第一座铁桥。1873年他创办了杰·埃德加·托马森钢铁厂。
这个新厂从开张起就很成功。在十六年中，美国炼的钢比英国的多，尽管英国炼钢比美国早得多。1888年，安德鲁·卡内基买进了跟自己的厂差不多一样大的一家钢厂和匹兹堡附近另外几家钢厂的大部分股权。他把所有这些公司联合成为卡内基有限公司。这个机构包括矿山、钢厂、船舶和铁路，把原料从全国各地运入匹兹堡并把成品钢材运走。卡内基有限公司拥有炼钢和销售钢材所需的一切手段。1901年，他的公司估价五亿美元，卖给由美国著名银行家约翰·皮埃庞特·摩尔根创办的美国钢铁有限公司。那时摩尔根先生就说，卡内基是“世界上最富有的人”。他是从每星期挣一美元二十美分发展到这步田地的。