The boards of supervisors of the several counties and the legislative bodies of the several cities within the state of Michigan, or any of them, are hereby authorized and empowered to appropriate moneys out of the general fund of said counties or cities to an amount not exceeding $1,000.00 in any 1 year for the purpose of contributing towards the expenses of conventions to be held within the county or city, during the year, by the several congressionally chartered organizations of veterans who have served the United States of America during the time when the United States of America was at war: Provided, That in counties or cities now or hereafter having a population of 50,000 or over, as determined by the last federal decennial census or by any federal decennial census hereafter taken, the boards of supervisors of such counties and/or the legislative bodies of such cities, or any of them, are hereby authorized and empowered to appropriate moneys out of the general fund of such counties or cities, to an amount not exceeding $5,000.00 in any 1 year for such purposes: Provided further, That in counties or cities now or hereafter having a population of 500,000 or over, as determined by the last federal decennial census or by any federal decennial census hereafter taken, the boards of supervisors of such counties and/or the legislative bodies of such cities, or any of them, may appropriate not to exceed $25,000.00 for national conventions of said veterans’ organizations.