In January 1778, Governor Patrick Henry of Virginia authorized Col. George Rogers Clark to raise a regiment to fight in the west. Soldiers of the Illinois Regiment of Virginia Volunteers recruited from Virginia and Pennsylvania.
At the beginning of the campaign, Col. Clark established his headquarters at Old Redstone Fort (vic. Brownsville PA.) On 5/12/1778 Clark and three companies departed by boat down the Monongahela River for the Ohio. On 5/27/1778 at the Falls of the Oho, Clark rendezvoused with an additional undermanned company which had been recruited from the Holston River area of Virginia. The newly augmented regiment set up camp on Corn Island (vic. Louisville KY) which they fortified, and began training. And in June, the regiment departed down the Ohio.
On 7/4/1778 the Regiment captured Kaskaskia (now IL), a British post on the Mississippi River above St. Louis. Later Cahokia (now IL) and Vincennes (now IN) were captured. And, the Illinois Country was secured. But in December, British Lieutenant Governor Henry Hamilton took Vincennes back.
On 2/5/1779 Col. Clark and the Regiment departed Kanskaskia to retake Vincennes. After a two-day battle, Vincennes was retaken on 2/25/1779. The British survivors, including Gov. Hamilton, were transported to Virginia.
The next major project was establishing Ft. Jefferson at the confluence of the Ohio and Mississippi Rivers. By 5/1780 the fort was constructed and an adjoining town named Clarksville was started. From this point, the regiment settled down to occupying the forts on the Ohio and Mississippi, defending the frontier. In 6/1781 Fort Jefferson was abandoned, and many of the soldiers marched to the Falls of the Ohio where they were discharged.
After the victory at Yorktown, personnel numbers and funds for the Regiment were reduced. And finally in 1784, the Regiment was disbanded.
"The Illinois Regiment - Virginia State Forces," Historical WebPage, 2006 <http://www.illinoisregiment.org/timeline.htm> 4 April 2009.
Fort Near the Mouth of Ohio Contemplated
The establishment of a strong fort near the mouth of the Ohio had been for some time considered as essential to American success. Governor Henry, as far back as January, 1778, wrote that it was "in contemplation to establish a post near the mouth of the Ohio, with cannon to fortify it." Thomas Jefferson, who succeeded Henry as governor on the 1st of June of that year, renewed the project, and followed it up, vigorously, until consummated. The object, in part, was to strengthen the American claim to the country as far west as the Mississippi, and a line of forts was contemplated from Fort Jefferson northwardly, towards the lakes. Colonel Clark warmly approved the building of the fort near the mouth of the Ohio, and did what he could to carry it into execution, but it progressed slowly, of necessity. Some Kentuckians did not seem to favor it because it would weaken the settlements by drawing off a portion of the militia much needed nearer home. Colonel Clark's plan was not only to build and garrison a fort, but to induce families to settle there by liberal grants of land. He issued the following order, to that end, to Captain Silas Martin, soon after his return to the falls:
"SEPTEMBER 30, 1779. "G. R. Clark to Captain Silas Martin, etc., Commander of Militia Headquarters Falls of Ohio: "By George Rogers Clark, Esq., Colonel of the Illinois Battalion, Commander-in-Chief of the Virginia Forces in the Western Department, Etc., Etc. "Whereas a fort is intended immediately to be built near the mouth of Ohio, and a number of artificers wanting to carry on the works, as well other inhabitants, "I do, by the virtue of the power and authority to me given, authorize you to raise any number of persons that you can get to become settlers at said post, the whole to be under pay as militia as long as necessary. You are to rendezvous at this place by the first day of December next. Given from under my hand."
The fall and winter passed without building the fort, but in March, 1780, Colonel Clark reviewed the situation and developed his plans in the following letter to Colonel John Todd, the then governor of the Illinois country: "By the account from every post in the Illinois so nearly corresponding, I make no doubt of the English regaining the interest of many tribes of Indians, and their designs against the Illinois, perhaps on Governor Hamilton's plan, and without some speedy check may prove fatal to Kentucky and the total loss of the western country on the Mississippi. I am not clear but the Spaniards would fondly surfer their settlements in the Illinois to fall into ours for the sake of having the opportunity of retaking both. I doubt they are too fond (of) territory to think of restoring it again.
"Although there are but few British troops on the lakes (the) deficiency is fully replaced by the immense quantity of goods they have, the effects of which among the savages you well know. Not being apprehensive of a visit, I make no doubt of their having planned some expedition of importance against our posts, which, if they gain, may be attended with greater consequences than I have hinted at. They have greater opportunities of knowing our situation than we have of theirs, which you know they could not deprive us of. You well know the difficulties we have labored under with our joint efforts to maintain our ground, and support our interest among the savages in that department, and the reason why which is now greater than ever as the bad crops and the severity of the winter hath rendered it impossible for the towns in the Illinois to make any further supplies until next harvest
"The troops being entitled to a discharge in a few weeks, except those that have re-enlisted when joined by Captain Rogers when armed will not amount to more than one hundred and fifty, which is too few, under our present circumstances, to think of defending the different posts we now occupy. Letters from His Excellency, and a promising account from our recruiting officers may, perhaps, soon alter our apparent circumstances, but, as yet, receiving no advice from either, already meeting with many disappointments in my expectations, much to the disadvantage of the department, a few weeks' hesitation may be productive of long future disadvantage. I think it best to act as though we had no expectation of being assisted either with men or provisions. Your counsel, not only necessary, but which you know I prize, is what I want.
"If we were tolerably formidable at any one post that we could subsist at, it might have a great and good effect. As I hinted to lay aside all expectations of a re-enforcement, I see but the one probable method of maintaining our authority in the Illinois, which is this; by immediately evacuating our present posts, and let our whole force center at or near the mouth of Ohio, which will be too contemptible to answer the good effect proposed, without we fall upon some method to draw off a considerable re-enforcement from Kentucky of militia.
"Families would be of the greatest service, as they are always followed by two or three times their numbers of young men. They would with their store of provisions be able to victual great part of our troops in proportion to their number, which, if only one hundred, by the ensuing fall would be able to victual a regiment, besides establishing a post that His Excellency is very anxious for, the reason I imagine we are both acquainted with, and the interests of all the western country call for.
"One hundred families, their followers, the troops we have already engaged, those whose time of service is or shortly will expire, that would remain at the place, when joined, would be considerable. The report of which by the time it reached our enemies would be augmented, perhaps, to treble our numbers, as such intelligence is always aggravated by the Indians; and I don't doubt but that it would put a stop for some time to their proceedings, as I know it would greatly confuse the Indians they are like to win from us, as our temporary force, with the French militia, probably counting the Spaniards, would be too considerable for them to tamper with.
"Our only chance at present to save that country is by encouraging the families, but I am sensible nothing but land will do it. I should be exceedingly cautious in doing anything that would displease government, but their present interest, in many respects obvious to us both, call so loud for it, that I think, sir, that you might even venture to give a deed for forty or fifty thousand acres of land at said place, at the price that government may demand for it. It interferes with no claim of our friendly Indians (and would be) the greatest barrier to the inhabitants of the Illinois against the southern Indians security of the general commerce and perhaps the saving of the country to the state, and probably in a few months enable us to act again on the offensive.
"I should be against suffering families to settle promiscuously in any part of the Illinois at present, but the establishment of the said post is so necessary, and as it can not be complete without the families, I think it your duty to give the aforesaid encouragement and such instructions as would confine the people for some time to a fort. Before you could consult government it might be too late. Sustenance for some time will be procured with difficulty.
"I can not think of the consequences of losing possession of the country without a more determined resolution to risk every point rather than suffer it, for they, the English, can not execute any matter of very great importance among the savages without it. I know your concern to be equal to mine; if you concur with me in sentiment, let me know immediately, or such amendment as you might think more advantageous."
Colonel Todd approved these suggestions, and acted upon them, as will be seen from his letter to Governor Jefferson, in which he said: "On consulting with Colonel Clark, we found it impracticable to maintain so many posts in the Illinois with so few means and concluded it better to draw them all to one post. The land at the junction of the Ohio and Mississippi was judged best situated for the purpose as it would command the trade on an extensive country on both sides of each river and might serve as a check to any encroachments from our present allies, the Spaniards, whose growing power might justly put us upon our guard."
"Conquest of the Country Northwest of the River Ohio and the Life of Gen. George Rogers Clark," The University of Illinois, No date <http://www.archive.org/stream/conquestofcountr2engl/conquestofcountr2engl_djvu.txt> 4 April 2009.