The maximum supercurrent through a long and narrow Josephson junction has been calculated numerically as a function of an applied magnetic field for various feed current distributions. The results have been shown to depend drastically on the mode of the current feed. In particular, the real nonuniform distribution &eegr;ov(x) of the current corresponding to the overlap geometry of the junction is nearly equivalent to the mixturey&eegr;un+(1−y)&eegr;inwith the factoryapproaching unity as the junction length increases: (1−y)=Cy(L/&lgr;j)−0.5,Cy&bartil;1.7. In contrast with the static properties, the shape of the zero‐field step in the long junctionI‐Vcurve appears to be almost independent of the mode of the current feed, because of averaging of the Lorentz force by the travelling Josephson vortices.