When Washington marched to Cambridge (I believe) to take command of the new 'Continental Army' in 1775, he would have amassed large numbers of militia and volunteers from Virginia, Pennsylvania, and New York along the way. When he arrived, roughly how many men would have been in his train NOT including those men (from new engand) that were already encamped and surrounding Boston?
I guess an additional question would be how large would the combined army then have been once he arrived?
Thanks!
Washington did not bring many new soldiers with him when he went to take command of the army outside of Boston.
The Committee of Safety (which was the body which had overseen the army) reported on May 20 1775 that 24,000 men had been raised (as compared to 30,000 intended to be raised) for the army besieging Boston.
http://www.americanantiquarian.org/proceedings/44539557.pdf
These men mostly came from Massachusetts, with some from Connecticut, Rhode Island and New Hampshire.
Other than this reference, no other records of the size of the army at different points in time survive. (Though we have many records of General Ward requesting reports on the numbers in each unit from his unit commanders.)
Despite 24,000 men "having been raised", it is doubtful that the army was ever this large. We know from diaries that many men left the siege to return home for extended furloughs, and, despite the fact that men were not supposed to leave the army unless they found a substitute from their district, that many did leave without organizing a replacement.
This source:
http://www.army.mil/article/40819/Washington_takes_command_of_Continental_Army_in_1775/
estimates (by estimating numbers from the brigade structure which Washington proposed for the army - 28 regiments of 728 men each) that when Washington arrived in Cambridge on July 3 1775, the army numbered 20,372 men. (Mostly New Englanders, but including one proposed regiment of rifle men, indicating that some of the rifle companies had arrived.)
This proposed organization by Washington was never fully implemented, and it is unknown whether this theoretical army strength actually existed on the ground in July 1775.
The only troops from outside New England who arrived to support the siege of Boston that I have been able to find reference to were the rifle companies which the Continental Congress had authorized recruitment for from western Pennsylvania and Virginia.
Some 1400 to 2000 of these rifle men seem to have arrived in the army before the end of the siege of Boston.