The random sequential adsorption of parallel (aligned) squares is studied by computer simulation. A new precise value of the maximum (jamming) coverage is found: I9J =0.562 009+0.000004. The dynamics for times t ~6000 agree with Swendsen s prediction 0J—0(t)-c(lnt)/t. Various twopoint correlation functions are measured, and the effects of the finite size and the discretization of the adsorbing surface are also investigated.