Amplification before tubes and transistors were invented
It wasn't.

In the early days (ca 1890) long-distance telephony was done from sound-proofed booths and often using non-standard (4-wire) telephones. New York to Chicago was the limit on range. By 1911, the use of loading coils allowed communication from New York to Denver. Notice, though, that this was pretty frustrating and involved a lot of yelling.

In 1915 the first transcontinental call was made, with amplification using the audion vacuum tube.