Ada was designed in response to a US Department of Defense initiative which sought a common higher order language for all defense applications.

Jean Ichbiah's team at Honeywell Bull won the competition for the new language, which was named after Ada Augusta, daugther of Lord Byron and Countess of Lovelace. Ada was Babbage's assistant and thus may claim the title of the first computer programmer.

Ada is now an ANSI and ISO standard:

Reference Manual for the Ada Programming Language,
ANSI/MIL-STD-1815A-1983, Feb, 1983.

The language reference manual may also be found as an appendix in some texts, eg

J.G.P. Barnes, "Programming in Ada plus Language Reference Manual", 3rd ed, Addison-Wesley, 1991.
ISBN 0-201-56539-0.

The Ada initiative pre-dates the discovery of object-oriented design. However, it does support many OO design strategies. It provides excellent support for the construction of Abstract Data Types through use of the package and private data type facilities.

An object oriented Ada, "Ada 95", has been defined.

An on-line version of the Ada Language Reference Manual is available. It is also available from a number of other sites: any Internet search engine should be able to locate the nearest one for you.

A full set of Ada resources, the Ada rationale, the Ada Information Clearing House (Ada IC), etc, is available at the Swiss Federal Institute of Technology in Lausanne (EPFL)'s Ada Resources page.