Yet five years went by before Robert de la Salle (lah sahl') set forth with authority from the French King "to labor at the discovery of the western part of New France," and began the attempt to follow the river to the sea.

In 1678 La Salle and his companions left Canada, and made their way to the shore of Lake Erie, where during the winter they built and launched the _Griffin_, the first ship that ever floated on those waters.

In this they sailed to the mouth of Green Bay, and from there pushed on to the Illinois River, to an Indian camp not far from the site of Peoria, Ill.

Just below this camp La Salle built Fort Crevecoeur (cra'v-ker, a word meaning heart-break, vexation).
[Illustration: %FRENCH CLAIMS% MISSIONS AND TRADING POSTS IN MISSISSIPPI VALLEY %in 1700%] Leaving the party there in charge of Henri de Tonty to construct another ship, he with five companions went back to Canada.

On his return he found that Fort Crevecoeur was in ruins, and that Tonty and the few men who had been faithful were gone, he knew not where.