Electronic Commerce, commonly known as e-commerce, consists of the buying and selling of products and services over electronic systems such as the Internet and other computer networks.
In the late 1970s, Electronic Funds Transfer (EFT) and Electronic Data Interchange (EDI) were introduced.
Electronic funds transfer (EFT) is the computer-based systems that used to perform financial transactions electronically. However, it was limited to financial institutes, large corporations, and some daring businesses.
In 1968, the introduction of the Electronic Data Interchange (EDI) enables the companies to interface and trade without any human contact. However, EDI was not supported by most businesses as it lacks much significance as a medium of commerce and the cost of having it was tremendous.
The earliest example of many-to-many electronic commerce in physical goods was the Boston Computer Exchange, a marketplace for used computers launched in 1982.
In 1984, the ASC X12 standard was adopted, allowing for full communication between any EDI supported companies. The companies could now transfer information on its needs for supplies and receive demands from other companies directly through their computer systems. However, the scope of e-commerce is still unfulfilled.
The first online information marketplace, including online consulting, was likely the American Information Exchange, another pre-Internet online system introduced in 1991.
In 1992, CompuServe offers online retail products to its customers. This is the first time that the people are able to buy things off their computer. In the same year, Mosaic web-browser was available and it was the first “point and click” web-browser.
In 1994, Netscape was introduced to the public as an easy-to-use web browser that allowed common people to surf the net.
In 1995, Microsoft’s Internet Explorer soon followed and increased the number of Internet users to over 14 million. Amazon.com and eBay.com launched in this year.

At this time, people began to define the term ecommerce as the process of purchasing of available goods and services over the internet using secure connections and electronic payment services.
In 1999, the emphasis of e-commerce shifted from B2C to B2B.
By the end of 2000, a lot of European and American business companies offered their services through the World Wide Web. People began to associate a word "ecommerce" with the ability of purchasing various goods through the Internet using secure protocols and electronic payment services.
Although the internet became popular worldwide in 1994, it took about five years to introduce security protocols and DSL allowing continual connection to the Internet.
In February of 2000, some major players of e-commerce such as Yahoo, eBay and Amazon were attacked by the hackers. The attacks represent the need to improve the security in the development of e-commerce.
In 2001, the emphasis of e-commerce shifted from B2B to B2E, e-government, e-learning, and m-commerce.
In 2005, social networks started to rise and so did l-commerce and wireless applications.

Now, more and more people go online for the very first time. They’ll send email, chat, and, with any luck for e-busineses, shop. Retailers are counting on the number of people who use the Internet to increase with even more rapidity than in the past due to modern technology. The days of UNIX command-line language, the days of impossibly slow connections asnd the days of consumer apprehension are gone.
References:
http://iml.jou.ufl.edu/projects/fall01/hanson/
http://www.ecommerce-land.com/history_ecommerce.html