The first of these acts was passed in 1882, and provided for the exclusion of Chinese laborers for a period of ten years. This was not to apply to Chinese who were already in the country, or who should enter within ninety days after the passage of the act. Such persons, who desired to leave the country and return, were required to secure a certificate, which by an amendatory act of 1884 was made the sole evidence of the right of a Chinaman to return. This act also required a certificate of the exempt classes, to be issued by the Chinese government or such other foreign governments as they might be subject to. The deportation of Chinese unlawfully in the country was also provided for by these acts. These laws were in many respects carelessly drawn and extremely difficult of execution. In their application they entailed great expense upon the United States government, and worked extreme hardship and injustice to many Chinese. They were, nevertheless, effective as regards their main purpose, for the volume of Chinese immigration at once diminished exceedingly. The strictness of the exclusion was increased by the act of 1888, which refused return to any Chinese laborer unless he had a lawful wife, child, or parent in the United States, or owned property of the value of $1000 or had debts due him of like amount. The acts in force were extended for another ten years by the act of 1892, and again indefinitely in 1902, in each case with relatively unimportant modifications in detail.